Plain English
Tech glossary
Short, jargon-free definitions for the words that show up in how-tos.
.
- .reg file
- A plain-text file that adds, changes or deletes registry entries when you double-click it and confirm. You can open it in Notepad to read exactly what it will do before running it. See also: Registry (Windows)
3
- 3-2-1 backup rule
- Keep 3 copies of anything important, on 2 different kinds of storage, with 1 copy kept somewhere else (off-site or in the cloud). See also: Backup
A
- Administrator (admin) rights
- Permission to change things that affect the whole computer, such as installing drivers or system-wide settings. Windows asks you to confirm with a User Account Control prompt; on a Mac or Linux, commands that need it start with sudo and ask for your password.
- App
- Short for application: a program you use to get something done, like a web browser, an email program or a game.
B
- Backup
- A spare copy of your files kept somewhere else, such as an external drive or cloud storage, so you can get them back if the original is lost or damaged. See also: Cloud storage
- Bind mount
- Making a folder that already exists on one system appear at another path, for example a host folder showing up inside a container. Both paths point to the same files. See also: Container
- BIOS / UEFI
- The built-in software that starts a PC before the operating system loads. UEFI is the modern replacement for the older BIOS. See also: Operating system
- Bluetooth
- A short-range wireless connection for linking devices such as headphones, keyboards, mice and speakers.
- Browser
- The app you use to visit websites. Chrome, Edge, Firefox and Safari are all browsers. See also: URL
C
- Cache
- Temporary files an app or browser saves so things load faster next time. Clearing the cache can fix pages that display wrongly.
- Checksum (hash)
- A long fingerprint calculated from a file's contents, such as a SHA-256 hash. If even one byte changes the fingerprint changes, so matching checksums prove a copy is identical. See also: Backup
- Cloud storage
- Saving files on a company's servers over the internet (for example iCloud, OneDrive or Google Drive) so you can reach them from any device. See also: Backup
- Container
- A lightweight, walled-off space for running an app or a small Linux system on top of a host computer's own system. Docker and Proxmox LXC are common ways to run them. Unlike a virtual machine, a container shares the host's kernel. See also: Operating system
- Cookie
- A small piece of data a website stores in your browser to remember things like your sign-in or settings.
- CPU (processor)
- The chip that carries out a computer's instructions. It's often called the computer's brain. See also: RAM (memory)
D
- DNS
- The Domain Name System: the internet's phone book, which turns names like example.com into the numeric addresses computers use. See also: IP address
- Driver
- Software that lets the operating system talk to a piece of hardware, such as a printer or graphics card.
E
- Encryption
- Scrambling data so only someone with the right key can read it. It protects things like your Wi-Fi traffic and the files on a lost device.
- Ethernet
- A wired network connection made with a cable that plugs into your router. It's usually steadier than Wi-Fi. See also: Router
F
- File extension
- The letters after the dot in a file name, like .pdf or .jpg, which tell the computer what kind of file it is.
- Firewall
- A security feature that controls which network connections are allowed in or out of a device or network.
- Firmware
- Software built into a device such as a router, printer or phone. Firmware updates fix bugs and security problems.
G
- Group Policy
- A Windows feature for setting rules for a PC or its users, such as turning off a feature or locking a setting. Businesses manage it centrally. At home it's opened with gpedit.msc on Pro, Enterprise and Education editions, and most policies are stored as registry values. See also: Registry (Windows)
H
- HEIC / HEIF
- The space-saving photo format iPhones use by default. Macs open it natively; some Windows PCs need a free extension from the Microsoft Store to view it.
- HEVC (H.265)
- The space-saving video format iPhones record in by default. It keeps file sizes small, but older or some Windows PCs need an extra codec to play it.
I
L
- Live Photo
- An iPhone photo with a few seconds of video attached. Copied to a computer it usually becomes two files with the same name: a still image and a short .mov video.
M
- Malware
- Any software made to cause harm, such as viruses, spyware and ransomware. See also: Phishing, Ransomware
- Matter
- A shared smart-home standard that lets one device work with Apple Home, Google Home, Alexa and others, and be controlled over your home network rather than only through the maker's cloud. See also: Thread, Multi-admin
- mDNS
- Multicast DNS: the "who's there?" broadcasts devices use to find each other on a local network without a central server. Printers, AirPlay and Matter rely on it, and it often doesn't cross guest networks or VLANs. See also: DNS
- Multi-admin
- The Matter feature that lets one device be added to several smart-home apps at once (for example Apple Home and Google Home), each with its own secure group of devices, called a fabric. See also: Matter
O
- Operating system
- The main software that runs a device and its apps, such as Windows, macOS, Linux, iOS or Android.
P
- Password manager
- An app that creates and stores strong, unique passwords for you, locked behind one main password. See also: Two-factor authentication (2FA)
- Phishing
- A scam message, by email, text or a fake website, that tries to trick you into giving away passwords, money or personal details. See also: Malware
R
- RAM (memory)
- Short-term working memory a device uses for the apps that are open right now. More RAM lets more run smoothly at once. See also: Storage
- Ransomware
- Malware that locks or encrypts your files and demands payment. Good backups are one of the best defences. See also: Backup, Malware
- Registry (Windows)
- The database where Windows and many apps store their settings, organised into keys (like folders) and values (like files). Many hidden tweaks are just a registry value with no switch in Settings. See also: Group Policy, .reg file
- Restart (reboot)
- Turning a device off and on again. It clears temporary glitches and finishes installing many updates.
- Root squash
- An NFS file-sharing setting, on by default, that treats the client's all-powerful root user as an anonymous user, so root on one machine can't take over files on the server. See also: UID / GID
S
- Safe mode
- A way of starting a device with only the basics loaded, used to track down problems caused by other software.
- SSD
- Solid-state drive: fast storage with no moving parts, used in most modern computers. See also: Storage
- SSID
- The name of a Wi-Fi network: the name you pick from the list when connecting. See also: Wi-Fi
- Storage
- Where files and apps are kept long-term, even when the power is off, such as an SSD or hard drive. See also: RAM (memory), SSD
T
- Terminal (command line)
- A text window where you type commands instead of clicking. It's called Terminal on macOS and Linux, and PowerShell or Command Prompt on Windows.
- Thread
- A low-power mesh radio network for smart-home devices. Thread carries the messages and Matter is the language they speak. It needs a Thread border router to connect to the rest of your home network. See also: Matter, Thread border router
- Thread border router
- A device, such as a HomePod mini or a recent Nest hub, that links a Thread mesh to your Wi-Fi or wired network so phones and apps can reach the Thread devices. See also: Thread
- Two-factor authentication (2FA)
- Signing in with a second proof as well as your password, such as a code from an app or a text message, or a security key. It makes it much harder for someone who steals your password to get in. See also: Password manager
U
- UID / GID
- The numbers Linux and macOS use for a user (user ID) and a group (group ID). File permissions follow the numbers, not the names, so the same name can mean different people on two machines.
- URL
- A web address, such as https://oddbyte.me/topics. See also: Browser
- USB
- The common plug and port standard for connecting and charging devices. USB-C is the small, reversible version.
V
- VPN
- Virtual private network: an encrypted tunnel between your device and a server, often used on public Wi-Fi or to reach a work network.
W
- Wi-Fi
- Wireless networking that connects your devices to your router without cables. See also: Router, SSID
- WPA2 / WPA3
- Security standards that encrypt Wi-Fi. WPA3 is newer and stronger, and WPA2 is the fallback when WPA3 isn't available. See also: Encryption, Wi-Fi