Glossary

A glossary of work and digital tools

Short explanations of 271 terms: the core words from our columns — payroll, electronic records and OCR — plus the full security and cloud, web and networks sections. Terms that a column covers in depth link to it. The Japanese glossary is larger, with 1088 terms.

Working better

DX (digital transformation): Using digital tools to rethink how the work itself gets done. For a small company it starts not with choosing tools but with writing down current tasks one line at a time and seeing which run on paper, spreadsheets or email. More: Where to Start With DX in a Small Business
Groupware: Tools a team uses to share schedules, messages and files. Whether you need it depends less on headcount than on whether people are out, in other locations or working different hours — beyond the reach of a quick word. More: Does a Three, Five or Ten Person Company Need Groupware?
Knowledge silos (single-person dependency): When only one person knows how a task is done or where things are kept, so the work stops when they are away. Small rules — one written procedure, a fixed place for files, no shared accounts — start to reduce it. More: Five First Steps Away From "Only She Knows How"
SaaS: Software used as a service over the internet, usually in a browser and on a monthly or yearly plan. When too many pile up, review each one by asking whether anyone would clearly miss it. More: Too Many Tools: How to Decide What to Cut

People and attendance

Annual paid leave: Paid days off granted to employees who meet conditions such as length of service. Check the legal rules on taking leave against the labour authority’s own guidance. More: Paid leave: what happens when you track it separately from attendance
Attendance close: Fixing the month’s record of days worked, leave and overtime. Payroll runs on the closed record, so how cleanly the categories are separated at close decides how accurate everything after it will be. More: When Excel Stops Working for Attendance Tracking
Employee records: The record of each employee’s name, address, employment type, start date and so on. Holding the same details in several places lets them drift apart, so decide on one place as the source. More: Should HR Records and Payroll Live in One Place?

Pay, insurance and tax

Absence deduction: Deducting pay for days or hours of absence. Some salaried workplaces do this too, and the method belongs in the work rules or pay regulations. A day of paid leave must never be treated as an absence. More: Deducting pay for absence under a monthly salary
Allowances: Pay given for a specific reason or condition — a role, a qualification, housing, commuting. Calling something an allowance does not take it out of social insurance or income tax; what it actually is decides how it is treated. More: Base pay versus allowances: the name does not decide the treatment
Base pay: The core of an employee’s wage. Many companies use it as the basis for bonuses and raises, which gives it a different role from allowances. More: Base pay versus allowances: the name does not decide the treatment
Cut-off date and payday: The cut-off date ends the period of work a payslip covers; payday is when it is paid. The gap between them has to fit closing attendance, calculating, checking and the bank transfer. More: Setting the payroll cut-off and payday without squeezing the work
Lateness and early-leave deduction: Deducting pay for time not worked because of arriving late or leaving early. Taking more than the time not worked counts as a disciplinary pay cut under Japan’s Labour Standards Act, which has its own limits. More: Deducting pay for lateness and early leave, the same way every time
Payroll: The chain of work that turns attendance and employee records into gross pay, takes off social insurance, employment insurance, income tax and resident tax, and arrives at the amount paid. Each step feeds the next, so the source data matters most. More: Payroll, step by step: from closing attendance to paying out
Premium pay (overtime pay): Pay at an increased rate for statutory overtime, rest-day and late-night hours. Before calculating it, attendance has to settle which category each hour falls into. More: How overtime pay is calculated, and why attendance must sort it first
Special collection (resident tax): The employer deducts resident tax from monthly pay and pays it to the municipality. The employer does not calculate it: it deducts exactly the amount the municipality notifies. More: Resident tax by special collection, and why it is not income tax
Standard bonus amount: The figure health insurance and pension premiums on a bonus are calculated from. It is not the same basis as monthly pay, so the monthly formula should not simply be reused. More: What comes out of a bonus, and how it differs from monthly pay
Standard monthly remuneration: The figure Japan’s health insurance and employees’ pension premiums are calculated from. Housing and commuting allowances paid monthly with salary are normally included; what counts is the substance, not the name. More: How housing and commuting allowances count for social insurance
Withholding tax: The employer deducts income tax when paying wages and pays it to the state on the employee’s behalf. The monthly amount comes from the National Tax Agency’s withholding tables, not a flat rate, and the year is settled in the year-end adjustment. More: How the income tax withheld from salary is worked out
Year-end adjustment: Settling the gap between the income tax withheld over the year and the tax actually due for it. Preparation starts in autumn, checking each year’s tax changes and forms. More: Year-end adjustment: the payroll team's work from autumn to January

Documents and records

AI OCR: OCR that goes on to decide which field each piece of text belongs to — partner, date, amount. It cuts down retyping, but figures that lead to a payment still need a person to check them. More: OCR and AI OCR: What Each One Actually Does
Electronic Books Maintenance Act: The Japanese law setting the rules for keeping tax-related books and documents as electronic data, including data from electronic transactions. The details change from time to time, so check the National Tax Agency’s current guidance. More: Storing Electronic Transaction Data Is More Than a Folder of PDFs
Electronic transaction data: Invoices, receipts and similar records exchanged by email or online. Dropping them in a folder is not enough; Japan’s National Tax Agency describes measures against tampering and being able to search by date, amount and partner. More: Storing Electronic Transaction Data Is More Than a Folder of PDFs
OCR: Technology that turns the text in an image or scanned document into text a computer can work with. Accuracy depends more on the source image than on the software — resolution, skew and shadows all change the result. More: Seven reasons OCR misreads your documents
PDF splitting: Breaking one PDF that holds several documents into separate files by document or page. Finding, sharing and storing get easier. More: The office problems that splitting a PDF quietly solves

Files and data

Clipboard history: Keeping several things you copied instead of losing each one to the next. It helps wherever the same text gets retyped all day — though some things, such as passwords, should not be kept. More: How far clipboard history gets you at work, and what it must never keep
File naming rules: Agreeing one pattern for file names across the company. Ordering them as date_type_partner_amount, for example, sorts a folder by date the moment it opens and lets you find a file from part of its name. More: File naming rules that a whole company can actually follow

Security

3-2-1 rule: Keep three copies, on two kinds of storage, with one somewhere else. The point is not to lose everything in one accident. More: Cloud Sync Is Not a Backup
Access control: Deciding and managing who may reach which data and systems, and how far. Splitting permissions by role is the basic pattern. More: Stop making everyone an administrator: least privilege in a small team
Account takeover: Someone signing in with your ID and password and acting as you. Change the password and check the signed-in devices as soon as you notice.
Administrator rights: Powerful permissions that can change settings and install software. Doing everyday work from a non-admin account keeps any damage small. More: Stop making everyone an administrator: least privilege in a small team
Advertising identifier: An identifier a phone uses for advertising. iPhone and Android each have their own; you can usually reset it or stop apps from tracking you in settings. More: What Is AdFection? Zero-Click Attacks Through Ads, and Everyday Defences
Adware: Software that earns money by showing ads. Some of it keeps pushing ads or collects browsing data without asking.
Anonymization: Removing or altering names and other details so that data can no longer be traced to a person.
Antivirus software: Software that finds and removes malicious programs. Windows and macOS include one; keeping its definitions up to date is what matters.
Apps from unknown sources: Apps installed from outside the official app store. On Android, permission to install unknown apps is granted per app, so do not leave it switched on. More: Emails posing as the tax agency or points offers that push malicious apps onto Android
Audit log: A record of important actions kept so they can be checked later. Stored append-only so it cannot be altered.
Authentication: Checking that the person trying to use something is who they claim to be, using a password, a code, a fingerprint and so on.
Authenticator app: A phone app that shows one-time passwords. Harder to hijack than SMS, so it is a common choice for multi-factor authentication.
Authorization: Deciding what a person is allowed to do — view, edit and so on — after they have been authenticated. A separate step from authentication.
Backdoor: A hidden way into a system that skips the normal sign-in. Attackers often plant one after a first break-in so they can come back.
Backup: Keeping a copy of data as it was at a point in time, somewhere separate. Cloud sync keeps every device identical — deletions included — so it is not a substitute. More: Cloud Sync Is Not a Backup
Biometric authentication: Confirming who you are from a physical trait — fingerprint, face, veins. Nothing to remember; widely used to unlock phones.
Bots: Programs that visit websites automatically. Search engines and others visit every public site, so volume alone is not the issue; what matters is whether the server is slowing down or bots reach places they should not. More: Your Site Is Full of Bots. Which Ones Should You Block?
Brute-force attack: Trying every possible password one after another to break into an account. Long passwords, multi-factor authentication and a limit on sign-in attempts all help.
Business email compromise (BEC): Fraud in which someone poses as a client or an executive and asks for a payment, often with a “new” bank account. The defence is a rule that account changes are always confirmed by phone or another separate channel.
CAPTCHA: A test — reading distorted letters, ticking a box — that tells a person from a program. More: Your Site Is Full of Bots. Which Ones Should You Block?
Certificate authority: An organisation that issues site certificates and vouches that a site belongs to the named owner. Browsers and phones keep a list of trusted authorities and only accept certificates that chain to them. More: A certificate authority's weak keys, and how browsers stop trusting a CA
Certificate Transparency (CT): A system that records issued certificates in public logs anyone can check. Some browsers reject certificates missing from the logs, which makes secretly issued fake certificates easier to spot. More: A certificate authority's weak keys, and how browsers stop trusting a CA
Computer virus: A malicious program that spreads by inserting itself into other files. In everyday talk the word is often used for malware in general.
Cookie: A small piece of data a site stores in your browser, used for things like staying signed in. If it is stolen, someone can act as you.
Credential stuffing: Using ID-and-password pairs leaked from one service to try signing in to others. Not reusing passwords is the single best defence.
Cross-site scripting (XSS): Using a weakness in a site to plant a script that then runs in visitors’ browsers.
CSP (Content Security Policy): A setting a website sends to the browser listing where scripts, images and other resources may be loaded from. It makes it harder for an injected script to run. More: A Run of Unauthorised Access in Japan: What Should You Check on Your Own Website?
CSRF: Making a signed-in user perform an action they did not intend, such as a submission or a settings change. Short for cross-site request forgery.
CVE: A worldwide ID given to each published vulnerability (for example, CVE-2026-12345). Update notices and alerts use it, so you can look up information about the same flaw. More: Update notices and cyber attacks: what can wait and what to install now
Data breach: Information that should have been protected getting out. Not only attacks: a misaddressed email or a laptop left on a train will do it.
DDoS attack: Flooding a site or server with traffic from many devices at once so it stops working. A CDN or WAF in front absorbs much of it. More: Your Site Is Full of Bots. Which Ones Should You Block?
Defence in depth: Layering several measures instead of relying on one, so that if one layer is broken the next still holds.
Digital certificate: Data issued by a trusted certificate authority to prove that a site or a person is genuine. On an HTTPS site, the server’s certificate confirms you are connected to the right place.
Disk encryption: Encrypting a computer’s whole storage, so a lost device does not give up its data. BitLocker on Windows and FileVault on macOS are the usual examples.
Double extortion: A ransomware tactic that both encrypts data and threatens to publish stolen information unless a ransom is paid. Even if data can be restored, the data theft still has to be dealt with. More: Ransomware Protection: Does It Stop at "We Have Backups"?
EDR: Software that watches what happens inside computers and servers, stops suspicious behaviour and lets you investigate afterwards. Its point is a faster response once someone is already in.
Encrypted DNS: Sending DNS lookups (finding where a site name points) in encrypted form. It prevents eavesdropping, but lookups may then bypass DNS-based blocking or logging on the network. More: What Is AdFection? Zero-Click Attacks Through Ads, and Everyday Defences
Encryption: Transforming data by a set method so that only someone with the key can read it. Used to protect data in transit and files at rest.
End-to-end encryption: Encryption that can only be undone on the sender’s and the recipient’s own devices. The servers in between are built so they cannot read the content (what stays on the other person’s device, backups, and details such as who talked to whom and when are a separate matter).
Exploited in the wild: A vulnerability already known to be used in real attacks. If an alert says this, treat the update as one to install now, not later. More: Update notices and cyber attacks: what can wait and what to install now
Fake online shop: A site that poses as a real shop or official store to take orders it never ships or to steal card details. Prices far below the usual and company details you cannot verify are warning signs. More: When the site an AI suggests is fake: four checks before you buy
Firewall: A gate at the edge of a network that lets through only the traffic you allow. Built into computers and routers. More: What a WAF Is, and How It Differs From a Firewall
HTTPS: Encryption for the connection between a browser and a server, so it cannot be read or altered on the way. The padlock means the connection is encrypted — not that the site itself is safe. More: What HTTPS Does Not Protect You From
IDS / IPS: Systems that detect suspicious traffic and raise an alert (IDS), or go on to block it (IPS).
Impersonation: Pretending to be another person or a real company to extract information or payments. A display name in email is trivial to fake, so check the address and confirm through another channel.
Incident response: What you do when something goes wrong: first steps to contain the damage, investigation, recovery and reporting. Deciding in advance who to call keeps it calm.
Information security policy: The company’s written rules for how it protects information. For a small company, a handful of rules that will actually be kept is the realistic start. More: Security basics for a small company, in the order worth doing them
Insider threat: Employees, former employees or contractors taking data out or misusing it. Least privilege and a record of actions are the deterrents. More: Stop making everyone an administrator: least privilege in a small team
Intermediate certificate: A certificate between the root and a site’s certificate. Authorities normally issue site certificates with the intermediate’s key, so if that key leaks, fake certificates could be made. More: A certificate authority's weak keys, and how browsers stop trusting a CA
IP address restriction: Allowing access only from set locations, such as the office connection. It suits admin screens used from a fixed place, but on tools people use from home or on the move it tends to stop the work. More: Do You Really Need IP Address Restrictions?
ISMS: A management system for running and continually improving information security as an organization. Certification follows the international standard ISO/IEC 27001.
JVN: Japan’s vulnerability information site, run by JPCERT/CC and IPA. It gives each vulnerability an ID and lists affected products, versions and countermeasures. More: Update notices and cyber attacks: what can wait and what to install now
KEV (Known Exploited Vulnerabilities): A catalogue published by the US agency CISA of vulnerabilities confirmed as used in real attacks. It is used to decide what to fix first. More: Exploited flaws in parts of small business websites and online shops: what to ask your vendor
Keylogger: Software or a device that records keystrokes. Used maliciously it captures passwords, so avoid signing in to important accounts on a shared computer.
Least privilege: Giving each person only the access their work needs. It is not about distrust; it keeps the damage small when one account or device has a problem. More: Stop making everyone an administrator: least privilege in a small team
Lockdown Mode: An Apple feature for the small number of people who may face highly sophisticated targeted attacks. It limits some app and web features to reduce what can be attacked, which also affects everyday use. More: What Is AdFection? Zero-Click Attacks Through Ads, and Everyday Defences
Log: The record a system or app keeps of who did what and when. Essential for working out what happened after a problem.
Lost-device precautions: Preparing for a lost laptop or phone: screen lock, encryption, and the ability to lock or wipe it remotely.
Malicious app: An app that harms its user, for example by stealing information or controlling the device. It is often pushed through links in email or text messages; installing only from the official app store is the basic defence. More: Emails posing as the tax agency or points offers that push malicious apps onto Android
Malware: The general word for software written to do harm. It covers viruses, worms, trojans, ransomware and more.
Man-in-the-middle attack: Slipping between two parties to read or alter what they exchange. Encrypted connections, and never ignoring a certificate warning, are the defence.
Masking: Hiding part of what is shown on a screen, a document or in data — showing only the last four digits of a card number is the everyday example.
MDM: A system for configuring and managing the phones and laptops a company hands out, all at once — including locking a lost one and distributing apps.
Misdirected email: Sending an email to the wrong address. One of the commonest causes of leaks; a check before sending, or a short send delay, helps.
Multi-factor authentication: Signing in with something beyond a password, such as a phone prompt or a one-time code. A leaked password on its own is then not enough to get in. More: Security basics for a small company, in the order worth doing them
Offline backup: A backup kept somewhere disconnected from the network, so ransomware cannot encrypt it along with everything else. More: Cloud Sync Is Not a Backup
One-time password: A password that works only once and only for a short time. Delivered by an authenticator app or SMS and used to confirm a sign-in.
Online identity verification (eKYC): Completing identity checks online, for example when opening an account. Methods include sending images of ID documents and reading the document’s IC chip. More: Got a "data leak" notice? What to watch for when your information was exposed
Open redirect: A flaw that lets a legitimate site’s URL forward people to another site. Because the address starts with the real domain, it is easy to abuse for leading people to fake sites. More: Exploited flaws in parts of small business websites and online shops: what to ask your vendor
OS command injection: An attack that abuses poor input handling to run the attacker’s commands on a server. If it succeeds, the server may be taken over. More: Exploited flaws in parts of small business websites and online shops: what to ask your vendor
OS update: Moving Windows, macOS, iOS or another operating system to a newer version. Updates carry fixes for vulnerabilities as well as new features. More: Security basics for a small company, in the order worth doing them
Passkey: Signing in with your device’s face or fingerprint recognition instead of a password. Because a passkey does not work on a fake site, it resists phishing.
Passphrase: A long password made of several words strung together. Easier to remember than random characters, and still hard to guess.
Password manager: A tool that stores many passwords safely and fills them in for you, which makes a different long password for every service practical. More: Security basics for a small company, in the order worth doing them
Password reuse: Using the same password on several services. One leak then opens every other account at once.
Penetration test: A test that attempts a break-in using the same methods as a real attacker, to see whether the defences hold.
Personal information: Information that identifies a living individual: name and address, but also data that identifies someone when combined with other data. Check the handling rules with the Personal Information Protection Commission.
Phishing: Email or text messages that pose as a real company or service and lead you to a fake site to type in your ID, password or card number. The basic defence: check the sender and the link’s destination before you click.
Privacy Mark: A Japanese certification mark granted to businesses that have proper arrangements for handling personal data.
Ransomware: Malware that encrypts the files on a computer or server so they cannot be used, then demands a ransom to restore them. A backup kept in a separate, disconnected place — not sync — is what you recover from. More: Cloud Sync Is Not a Backup
Redaction: Removing the text or images you do not want to share from a document itself. Placing a black box over them only hides them; the text underneath may still be in the file. More: Blacked Out a PDF? What to Check Before You Send It
Remote wipe: Erasing the data on a lost device from somewhere else, for example through a phone’s “find my device” feature.
Risks of free Wi-Fi: On open Wi-Fi your traffic can be read, or you may connect to a fake access point. For anything important, tethering to your phone lowers the risk.
Risks of USB sticks: Handy to carry, and just as easy to lose or to carry a virus in on. For data that leaves the office, encrypt it or use your cloud service’s sharing instead.
Root certificate: The certificate at the base of an authority’s trust. It ships with the browser or OS, and trust flows from it through intermediate certificates to site certificates. If a browser removes it, certificates that chain to it are no longer trusted. More: A certificate authority's weak keys, and how browsers stop trusting a CA
Screen lock: Making a device unusable without a password or biometric check when you step away. Set it to lock automatically after a short time.
Security incident: A security accident — a data leak, unauthorized access, a malware infection — or an event that could become one.
Security patch: A fix released to close a vulnerability. It usually arrives as part of an OS or app update, and not putting it off is the basic defence.
Security question: A question used to confirm identity when a password is forgotten. Avoid answers that can be looked up; use one nobody else knows.
Session hijacking: Stealing the token that shows you are signed in, then using the service as you.
Shared account: One ID and password used by several people. Nobody can tell who did what, and leavers still know the password — so give each person their own account where you can. More: Five First Steps Away From "Only She Knows How"
Shoulder surfing: Reading a screen or keyboard from behind or beside someone to steal a password. A privacy filter helps when you work in a café or on a train.
SIEM: A system that gathers logs from many devices and applications and analyses them for signs of an attack.
Single sign-on (SSO): One sign-in that opens several connected services. Fewer passwords to manage, and a leaver’s access can be switched off in one place.
Smishing: Phishing by SMS. Common disguises are missed-delivery notices and unpaid-bill warnings. Ignore the link in the message and open the official app or your own bookmark instead.
Social engineering: Getting information by playing on people rather than technology — a phone call posing as a colleague, a glance at a screen.
Spam: Unsolicited bulk email, mostly advertising. Phishing and virus-carrying messages travel in it too.
Spear phishing: An attack email written for one company or person, posing as a client or a manager. The wording looks natural, so a rule that attachments and payment requests are confirmed with the person through another channel is what works.
SPF / DKIM / DMARC: Settings that let receiving servers check whether an email really came from your domain. With them in place, forged mail in your name is less likely to reach anyone.
Spyware: Software that quietly collects what you type and what you browse, then sends it out without your knowledge.
SQL injection: Typing crafted text into a form to manipulate the database behind a site. Prevented by never using input as-is when the site is built. More: What a WAF Is, and How It Differs From a Firewall
SSL/TLS: The mechanism that encrypts internet traffic; HTTPS is built on it. What is used today is TLS, but the older name SSL is still common. More: What HTTPS Does Not Protect You From
Supply-chain attack: Getting into a well-defended company by way of its suppliers or the makers of the software it uses, rather than attacking it directly.
Tech support scam: A trick that shows a fake warning such as "your device is infected" and pushes you to call the number on screen, then install remote-control software or pay. Never call the number shown.
Tracking (advertising): Linking information collected in one app or website with information from other companies’ apps and sites, for advertising or measurement. Phones and browsers often let you limit it in settings. More: Why Are Free Apps Free? Reading Ads, Pricing and Data Use
Trojan horse: A malicious program disguised as a useful app or a legitimate file. Once inside, it steals data or lets someone control the machine from outside.
Two-step verification: Signing in with a password and then confirming again with a code sent to your phone or similar. The most common form of multi-factor authentication.
UTM: One appliance that bundles a firewall, antivirus, spam filtering and more. Short for unified threat management; common in small offices.
VPN: An encrypted private tunnel over the internet. Used, for example, to reach office systems from outside.
Vulnerability: A weakness in software or in its settings that can be exploited for an attack. Also called a security hole. Most are closed by updates.
Vulnerability assessment: Having tools or specialists check a site or system for weaknesses. Done before launch and after major changes.
WAF (web application firewall): A layer that inspects what arrives at a website or app and blocks harmful requests. A conventional firewall decides which doors are open; a WAF looks at what is coming through the open ones. More: What a WAF Is, and How It Differs From a Firewall
Web shell: A file an attacker plants on a compromised web server to send it commands from outside. Once planted, it can be used even after the original hole is fixed, so traces need checking.
Worm: A malicious program that spreads on its own over a network rather than by attaching to files. Devices that have stopped installing OS updates are the easiest targets.
Zero trust: The principle that being inside the office network proves nothing, so every access is verified every time. It spread as cloud services and remote work grew.
Zero-click attack: An attack that exploits a vulnerability in a device or app without the user clicking a link or opening a file. Keeping the OS and apps up to date is the basic defence. More: What Is AdFection? Zero-Click Attacks Through Ads, and Everyday Defences
Zero-day attack: An attack that exploits a newly found weakness before a fix has been released. Installing the fix as soon as it appears shortens the window in which you can be hit.

Cloud, web and networks

404 error: The message shown when a requested page cannot be found. It appears when old links survive a page being moved or deleted.
Access point: The device that broadcasts Wi-Fi and connects wireless devices to the network.
Admin panel: The operator-only screen for changing a site’s or service’s settings. Guard its address and password, and restrict where it can be reached from if you can. More: Do You Really Need IP Address Restrictions?
API: The defined doorway through which software and services exchange data and functions. Used when connecting one service to another.
APOUL LCC (Life Connect Cloud): APOUL’s approach of combining the convenience of the cloud with the speed, reassurance and freedom of working locally: what can stay on the device stays there, and what needs sharing or syncing goes to the cloud. Read it on the About page
Bandwidth: How much data a line can carry at once. More bandwidth moves large data faster.
bps: Bits per second: the unit for how much data moves in one second, used for line speed as in “100 Mbps”.
Browser: The software you view websites with: Chrome, Safari, Edge, Firefox and others.
Browser extension: A small add-on that gives a browser extra features. Useful, but some can read what you browse, so keep to the ones you need.
Business chat: A tool for shorter, more casual work messages than email: Slack, Teams, LINE WORKS and others. More: Does a Three, Five or Ten Person Company Need Groupware?
Cache: Keeping a copy of data already loaded so it shows faster next time. If a page looks old after an update, the cache is often why. More: Does updating your website too often cause problems?
CC / BCC: Fields for people who receive a copy besides the main recipient. Addresses in BCC are hidden from the others, which is why it is used for group mail to outside contacts.
CDN: Copies of a site’s files placed on servers around the world so they are delivered from near the visitor. Faster, and better under heavy traffic.
Client: The device or software that sends requests to a server and receives the results. A browser is a web client.
Cloud: Using server capacity on the other side of the internet, as much as you need, without running a server yourself — for storing files, running apps and more. More: Cloud or local? You do not have to pick a side
Cloud and local: Whether work runs on an online service (cloud) or on your own device (local). Sharing and working on the move suit the cloud; speed, offline use and keeping things private suit local — and you can choose per task. More: Cloud or local? You do not have to pick a side
Cloud computing: Doing computation and storage on internet services rather than on your own equipment. The formal name for “the cloud”.
Cloud storage: A service that keeps your files on the internet so any device can open the same ones. Note that sync and backup do different jobs. More: Cloud Sync Is Not a Backup
CMS: A system that lets you update a site’s text and images without technical knowledge. WordPress is the best-known example. More: What should a small business build its website with?
Crawler: A program that visits and reads pages across the internet automatically. Search engines’ crawlers are the best known. More: Your Site Is Full of Bots. Which Ones Should You Block?
Data centre: A building built to run large numbers of servers safely, with managed power, cooling and access.
DNS: The system that turns a name like “apoul.jp” into the IP address machines use. Often called the internet’s phone book.
DNS record: One line of settings tying a domain name to an IP address, a mail server or similar.
Domain: The internet name used for a site or email addresses, such as “apoul.jp”, registered by its owner.
Domain renewal: The periodic step of renewing a registered domain so you keep it. Forget it and your site and email can stop.
Edge computing: Processing data close to where it is used instead of sending it to a distant cloud, for faster response and less data sent. More: Cloud or local? You do not have to pick a side
Email: Sending text and files over the internet. A sent message cannot be recalled, so check before you send.
Favicon: The small site icon shown in a browser tab or bookmark.
Freemium: A model where the basic features are free and more features or capacity are paid for.
Homepage: Strictly the first page of a site, though in Japan the word is often used for a whole website.
Hosting: Providing the place — the server — where a site or service lives.
HTTP: The rules a browser and a web server follow to exchange pages. The encrypted version is HTTPS. More: What HTTPS Does Not Protect You From
HTTP status code: The three-digit number a server returns to say how a request went: 200 means success, 404 not found, 500 a server fault.
Hybrid cloud: Combining cloud with your own equipment or local devices, placing each job where it fits. More: Cloud or local? You do not have to pick a side
IaaS: Cloud that rents you the foundations — servers, networking — over the internet. What you put on them is up to you.
IMAP / POP: Two ways of receiving mail. IMAP keeps messages on the server so every device sees the same state; POP downloads them to the device.
Index: A search engine reading a page and registering it so it can appear in results.
Integration: Connecting separate services so data moves between them automatically, sparing you from typing the same thing in several places. More: Too Many Tools: How to Decide What to Cut
Internet: The worldwide network made of networks connected to one another.
IoT: Connecting all kinds of things — appliances, sensors — to the internet.
IP address: The number assigned to each device on a network, used as the destination for traffic. More: Do You Really Need IP Address Restrictions?
IPv6: The newer form of IP address, created because IPv4 numbers ran out. It offers a vastly larger supply.
LAN: A network within a limited area, such as an office or a home.
Landing page: The first page a visitor sees after an ad or a search — often a long, single-purpose page for one product or sign-up.
Latency: The delay between sending data and its arrival. In video calls and online games it matters as much as speed.
Local: On the computer or phone in front of you. “Save locally” means on the device, not on the internet. More: Cloud or local? You do not have to pick a side
Mailing list: One address that forwards a message to everyone registered on it.
Maintenance: The inspection and update work that keeps a service or device healthy, sometimes done during a scheduled shutdown.
Mesh Wi-Fi: Several units placed around a home or office to cover it like a net, removing the dead spots.
Modem / ONU: The device that turns the signal from a fibre or other line into something your router and computers can use. Usually supplied by the line provider.
MX record: The DNS setting that says which server receives mail for a domain.
Name server: The server that answers which IP address a domain name points to, and so decides which service manages the domain.
NAS: A storage device attached to the network for several people to use — a common way to share files in an office.
On-premises: Running servers and software inside your own building. The opposite of cloud. More: Cloud or local? You do not have to pick a side
Outage: A system or service stopping, or no longer working correctly.
PaaS: Cloud that also provides the platform an app runs on (OS, runtime), so developers can concentrate on the app itself.
Page speed: How long a page takes to display. Right-sizing images is often the biggest single improvement.
Permalink: A page’s or post’s URL that is meant never to change. Change it and old links and search rankings can break.
ping: Sending a tiny signal to another machine and timing the reply. Used to check a connection and gauge delay.
Private cloud: A cloud environment set up for one company alone. More control, at more cost and effort.
Private IP address: An IP address used only inside an office or home network, not directly visible from the internet.
Proxy: A relay that connects to the internet on a device’s behalf, used to manage a company’s traffic in one place.
Public cloud: Cloud services for the general public, where many customers share the same infrastructure.
Public IP address: The IP address that is unique on the internet and identifies you from outside — assigned per office line. More: Do You Really Need IP Address Restrictions?
Redirect: Automatically sending anyone who opens one address on to another. Used when a page’s address changes.
Responsive design: Building a page so its layout and sizes adapt to the screen width, so it reads well on a phone too.
robots.txt: A file that tells crawlers which parts of a site they may read. Compliance is up to the crawler; it is not a way to protect anything. More: Your Site Is Full of Bots. Which Ones Should You Block?
Router: A device that joins networks together and directs traffic between them. A home router is the doorway to the internet.
Search Console: Google’s free tool for seeing how your site is treated in search: which pages are indexed, and which queries bring visitors.
SEO: Shaping a site’s content and structure so search engines can find and present it. Short for search engine optimization.
Server: A computer that serves pages, data or functions to other machines on request.
Share link: A link that lets anyone who has it see a file kept in the cloud. Some can carry an expiry date or a password.
Shared hosting: Renting a server to publish a site on, usually by the month, typically with one machine shared among many customers.
Sitemap: A list of the pages on a site: a page for people to read, and a file (sitemap.xml) for search engines.
SLA: A service-level agreement: what quality the provider commits to, such as uptime and response times.
SSL certificate: The digital certificate that identifies a site’s operator and enables HTTPS encryption. Some services issue them free. More: What HTTPS Does Not Protect You From
Static site: A site that serves pre-built page files as they are. Fast to display, with few openings for attack. More: What should a small business build its website with?
Status page: A public page that shows whether a service is running normally or having an outage right now.
Subdomain: A separate name made by adding a word in front of a domain, such as “shop.example.jp”, used to split things by purpose.
Subscription: Paying monthly or yearly and using a service only while you pay. Often shortened to “sub”. More: Too Many Tools: How to Decide What to Cut
Sync: Keeping data identical across several devices or services. Deletions sync too, so it is not a substitute for backup. More: Cloud Sync Is Not a Backup
Tethering: Connecting a laptop or other device to the internet through your phone’s data. Handy when you would rather avoid free Wi-Fi.
Uptime: The share of time a service is running and usable. One yardstick when choosing a cloud service.
URL: The address that says where a site or page is on the internet — the string beginning “https://”.
URL shortener: A service that replaces a long URL with a short one. Legitimate notices use them too, but you cannot see the destination at a glance, so check the address after the page opens. More: Is That QR Code Safe to Open? What to Check After Scanning
Video conferencing: Meeting people at a distance over the internet with video and audio: Zoom, Google Meet, Teams and others.
VPS: One physical server divided into virtual ones that each behave like your own. More freedom than shared hosting.
WAN: A wide-area network linking distant sites. The internet is one.
Web font: A typeface delivered by the site itself so it shows even when the viewer’s device does not have it installed.
Web page: A single page as shown in a browser, each with its own URL.
Webhook: A mechanism that automatically notifies a chosen address when something happens in a service.
Webmail: Email you read and write in a browser — Gmail, for example — usable from any device with nothing to install.
Website: A collection of pages published together under one domain or similar.
WHOIS: A lookup that shows who registered a domain. Personal details can usually be replaced with a proxy listing.
Wi-Fi: Wireless networking that connects devices without cables.
WordPress: The most widely used CMS in the world. Very flexible, but the core and its plugins need continual updating. More: What should a small business build its website with?

Phones and mobile

4G: The fourth generation of mobile networks — the standard that made video and maps on a phone an everyday thing. It is still widely used after the spread of 5G.
5G: The fifth generation of mobile networks: designed to be faster than 4G, with less delay and room for many more devices at once (real speeds vary with place and congestion).
APN (access point name): The setting that tells a phone which carrier’s network gateway to use for mobile data. After switching to a low-cost SIM, data may not work until this is set. More: What Is a Low-Cost SIM? Why It Is Cheaper Than the Major Carriers
Base station: The antennas and equipment placed around an area to exchange radio signals with phones. A crowded nearby station, or weak signal deep inside a building, can slow your connection.
Best effort: Providing service as fast as possible without guaranteeing a speed. An advertised “up to” speed is a theoretical maximum; real speed varies with congestion and location. More: Why Low-Cost SIMs Can Slow Down at Certain Times of Day
Carrier: A company that provides mobile phone service. In everyday Japanese, the word usually means the big carriers that run their own networks (MNOs). More: MNO vs MVNO: How Budget SIM Plans Work in Japan
Carrier email: An email address a mobile carrier gives its subscribers (common in Japan). It normally stops working when you switch carriers, though some carriers offer a paid way to keep it. Check your carrier’s terms.
Data cap (speed throttling): Having your speed slowed after you use up your plan’s data allowance, among other cases. When speed returns and how to buy more data differ from plan to plan.
Data roaming: Using mobile data through a local carrier’s network where your own carrier has no coverage, such as abroad. Charges can be high, so check the setting and the rates before you travel.
Data usage: How much data a phone has sent and received over the mobile network. Video uses a lot depending on quality and time. You can check it in phone settings or your carrier’s app. More: How Far Do 3GB, 10GB and 30GB Go? A Rough Guide to Data Use
Dual SIM: Using two lines on one phone. A common setup pairs a physical SIM with an eSIM — for example, keeping a work number and a personal number on one device. More: What Is an eSIM? How It Differs and What to Watch When Upgrading
eSIM: A rewritable SIM built into the phone itself. Instead of swapping cards, the plan’s details are downloaded over the internet. Sign-up and activation can often be done without visiting a shop. More: What Is an eSIM? How It Differs and What to Watch When Upgrading
Find-my-device features: Features that show a lost phone on a map, play a sound, lock it or erase it. On iPhone it is Find My; on Android it is Find Hub. They must be turned on beforehand. More: Lost Your Phone? What to Do First, in Order
IMEI: A 15-digit number that identifies each individual mobile device. You can find it in the phone’s settings or on the label on the box. It is used for repairs, reporting a lost phone and checking a second-hand device.
Interconnection fee: In Japan, what an MVNO pays a major carrier (MNO) to use its network. It is paid according to the capacity (bandwidth) rented, which affects speeds when many users are online. More: Why Low-Cost SIMs Can Slow Down at Certain Times of Day
Low-cost SIM: In Japan, the common name for mobile plans cheaper than the major carriers’, mostly offered by MVNOs that rent network capacity from them. Compare speeds at busy times and how support works, not just price. More: What Is a Low-Cost SIM? Why It Is Cheaper Than the Major Carriers
LTE: One of the standards used for mobile data on smartphones. In Japan it is often used to mean much the same as 4G, and a phone’s status bar shows one or the other.
Mbps: A unit of connection speed: how many million bits can be sent per second. It is not the same as MB (megabytes), used for file sizes; one byte is eight bits.
MNO (mobile network operator): A carrier that builds and runs its own mobile network, base stations and all. In Japan, the Ministry of Internal Affairs and Communications names NTT Docomo, KDDI, SoftBank and Rakuten Mobile as examples. More: MNO vs MVNO: How Budget SIM Plans Work in Japan
MNP (mobile number portability): The system that lets you move to another carrier and keep your phone number. In Japan, your current contract is not cancelled until the new one is complete. More: What Is MNP? Switching Mobile Carriers in Japan Without Changing Your Number
MVNO (mobile virtual network operator): A provider that has no large network of its own and sells mobile service on capacity rented from an MNO. Most low-cost SIM plans in Japan work this way. Speeds can drop at busy times of day. More: MNO vs MVNO: How Budget SIM Plans Work in Japan
No service: When a phone cannot receive a mobile signal, so calls and mobile data do not work. Besides location and signal, phone settings or the line itself can be the cause. More: Phone Suddenly Shows No Service? What to Check
One-stop MNP: In Japan, a way of switching carriers with your number by applying only to the new carrier. It began on 24 May 2023 and removes the step of getting a porting reservation number from your current carrier. Where a carrier does not support it, the older two-step method applies. More: What Is MNP? Switching Mobile Carriers in Japan Without Changing Your Number
Online-only brand: In Japan, a major carrier’s brand that handles sign-up and support mainly on the web or in an app. As of September 2026 these include Docomo’s ahamo, KDDI’s povo and SoftBank’s LINEMO. If you want help in a shop, check first whether it is available. More: What Is a Low-Cost SIM? Why It Is Cheaper Than the Major Carriers
RCS: A next-generation messaging standard that keeps phone numbers as the address but adds longer messages, photos and read receipts. Whether you can use it depends on your phone and carrier.
SIM: A small chip card that holds the details identifying a mobile subscriber. Put it in a phone and that plan’s phone number and data work on it. Cards come in more than one size, so it has to match the phone. More: What Is a SIM Card? How Your Phone Gets on the Network
SIM lock: A restriction that makes a phone work only with SIMs from the carrier that sold it. In Japan, SIM locks are in principle banned on phones released from October 2021. Older phones from the three big carriers may still be locked; unlocking online is free. More: What Is a SIM Card? How Your Phone Gets on the Network
SIM-free (unlocked): A phone with no SIM lock, so any carrier’s SIM fits. Carriers use different radio frequencies, though, so a SIM that fits may still get a weak connection.
SMS: Short text messages sent to a phone number. They are often used for login codes, and also for scams posing as missed-delivery notices, so take care with links.
Sub-brand: In Japan, a lower-priced brand a major carrier runs under a separate name. As of September 2026, KDDI’s UQ mobile and SoftBank’s Y!mobile are the best-known. More: MNO vs MVNO: How Budget SIM Plans Work in Japan
VoLTE: A way of carrying voice calls over a 4G (LTE) network. Calls tend to sound clearer than on older systems. On some phones, the APN has to be set before VoLTE works.

Computers and phones

Accessibility: Making information and services usable by everyone, whatever their age, disability or circumstances. Screen reading, larger text and keyboard-only use become necessary for anyone once conditions change. More: Accessibility is not only for a small group of people