Tech Glossary A–Z
Every word we’ve decoded, in one place.
Press Enter to jump to the first match.
A
Adware
Software that shows you unwanted ads — sometimes installed quietly alongside a free program. Usually annoying rather than dangerous, but a sign something was installed without your knowledge.
Algorithm
A set of step-by-step instructions a computer follows to finish a task, like sorting your email or choosing which video to show next.
Alpha
An early, rough version of software given to a small group to test. Things break, and that is expected — feedback helps the builders fix problems before a wider release.
Antivirus
A program that watches for and removes harmful software on your device. Most phones and tablets already have built-in protection, so you rarely need extra antivirus on those.
API
A set of rules that lets one program talk to another — for example, how your weather app pulls the forecast from a weather service.
App
Short for "application" — a program you open to get something done, like email, maps, banking, or games.
Archive
A single file that bundles many files together — often shrunk in size. You "unzip" or "extract" it to get the files back out.
Authentication
The process of proving you are who you say you are — typing a password, entering a code from a text, or using your fingerprint.
B
Backup
A spare copy of your files kept somewhere safe, so you can get them back if your device is lost, stolen, or broken.
Bandwidth
How much data your internet connection can handle at once. Think of it like lanes on a highway — more bandwidth means more traffic can flow without slowing down.
Beta
A mostly-finished version of software shared publicly for testing. It usually works, but you may still run into bugs before the final release.
Binary
The two-symbol language (0s and 1s) that computers use to store and process everything — text, photos, music, anything.
BIOS
The very first software that runs when you press the power button on a computer — it wakes up the hardware before the operating system loads.
Bit
The smallest unit of digital information — a single 0 or 1. Eight bits make one byte.
Bluetooth
A wireless way for nearby devices to talk to each other — like your phone connecting to wireless headphones, a car, or a speaker.
Bookmark
A saved shortcut to a website inside your browser, so you do not have to type the address again.
Boot
The process of turning on a computer or phone and loading the operating system so you can use it. "Rebooting" just means turning it off and on again.
Browser
The app you use to visit websites — Chrome, Safari, Firefox, or Edge are the most common ones.
Browser Engine
The part of a browser that reads a website and turns it into what you actually see — text, buttons, images, colors.
Buffering
When a video or song pauses to load more of itself before continuing. Usually caused by a slow internet connection.
Bug
A mistake in software that makes it behave in a way the builders did not intend — like a button that does nothing, or a page that crashes.
Byte
A small unit of digital storage made of 8 bits. File sizes are measured in bigger chunks of bytes (kilobyte, megabyte, gigabyte).
C
Cache
A stash of temporary files your device keeps so things load faster the next time you open them. Clearing the cache sometimes fixes broken pages.
CAPTCHA
A quick test — like picking all the traffic lights in a grid, or typing wobbly letters — that proves you are a real person and not a bot.
Catfish
Someone online pretending to be a different person, often to trick you into a relationship or into sending money. Reverse-searching their photos can help you spot one.
Cellular Data
Internet you get from your phone carrier (like Verizon or AT&T) through cell towers — the kind that works when you are away from Wi-Fi.
Chatbot
A program you type or speak to that answers back in plain language. Useful for simple customer service questions, but not always right.
Cloud
Storing your photos, files, or email on computers owned by a company (like Google, Apple, or Microsoft) instead of only on your own device — so you can reach them from anywhere.
Codec
The recipe a device uses to shrink a video or audio file so it can be sent or stored, then un-shrink it for you to watch or listen to.
Compression
Shrinking a file to take up less space — like folding up a big map so it fits in your pocket, then unfolding it later.
Cookie
A tiny file a website saves in your browser to remember things like your login, your cart, or your language choice.
CPU
The "brain" of your computer or phone that handles almost everything you do, one instruction at a time (but extremely fast).
Crash
When an app or device suddenly stops working and closes, freezes, or restarts on its own.
Crash Dump
A file your device saves when something crashes — it helps technicians figure out what went wrong. You usually never need to open it yourself.
Crypto Wallet
An app or small device that stores the secret keys you need to use cryptocurrency like Bitcoin. Lose the keys and you lose the money.
Cybersecurity
The practice of keeping your devices, accounts, and personal information safe from criminals online.
D
Dark Web
A hidden part of the internet that requires special software to visit. Most everyday people never need to go there; it is known for illegal activity and stolen data.
Data
Any information stored on a device or sent over the internet — photos, messages, passwords, everything.
Database
An organized collection of information a computer can search quickly — like a giant, searchable filing cabinet.
Desktop
Either (1) a regular non-portable computer that sits on a desk, or (2) the main screen of a computer where your icons and wallpaper live.
Developer Console
A hidden panel inside a browser that shows the behind-the-scenes code and errors of a website. Builders use it to hunt down bugs.
DNS
The internet's phone book — it turns friendly names like teksure.com into the numeric addresses computers use to find each other.
Domain
The name part of a web address, like teksure.com or nytimes.com. Every domain is registered to someone.
Download
Copying a file from the internet onto your device so you can use it — the opposite of upload.
DPI
Dots Per Inch — how many tiny dots make up a printed page or screen image. Higher DPI means sharper detail.
Driver
A small program that lets your computer talk to a specific piece of hardware, like a printer or webcam. An out-of-date driver is a common cause of printer trouble.
E
Email Client
The app you use to read and send email — Gmail, Apple Mail, and Outlook are common email clients.
Emulator
Software that pretends to be a different device or system, so you can run programs that were not built for what you have.
Encryption
Scrambling information so only the right person can read it. Your bank's website, messaging apps, and Wi-Fi password all use encryption.
Ethernet
A wired way to connect a computer to the internet using a network cable. It is usually faster and more stable than Wi-Fi.
Extension
A small add-on you install in your browser to give it extra features, like blocking ads or saving passwords.
F
File Extension
The three or four letters at the end of a file name (like .pdf, .jpg, .docx) that tell your computer what kind of file it is.
File System
The way your device organizes files into folders so it — and you — can find them again.
Firewall
A security guard for your network that blocks unwanted traffic from coming in or going out. Most home routers already have one turned on.
Firmware
The built-in software that runs inside a piece of hardware — your router, printer, or camera all have firmware. Updating it can fix bugs and add features.
Fork
When someone takes a copy of an existing software project and takes it in a new direction of their own.
Format
(1) The type of a file (like JPEG or PDF), or (2) wiping a drive clean to start fresh.
G
Gateway
The device (usually your router) that connects your home network to the wider internet — the doorway your data walks through.
GHz
Gigahertz — how many billion instructions per second a processor can handle. Higher is generally faster.
Gigabyte
A unit of storage roughly equal to a billion bytes. A 64 GB phone can hold around 15,000 photos.
GPS
A free satellite service that tells your device exactly where it is on Earth — the foundation of maps, rideshare, and location tracking.
GPU
A specialized chip that draws everything you see on screen — great at handling video, games, and graphics work faster than the main processor could.
H
Hard Drive (HDD)
An older style of storage that uses spinning magnetic disks. Cheaper but slower and more fragile than a solid-state drive.
Hardware
The physical parts of a device you can actually touch — the screen, keyboard, battery, cables, and so on.
Hash
A unique "fingerprint" calculated from a file or password. Change even one letter and the hash changes completely — useful for checking nothing was tampered with.
HDMI
The most common cable today for sending video and sound from one device to another — like a laptop to a TV or monitor.
Hotspot
A feature that turns your phone into a temporary Wi-Fi source so your laptop or tablet can get online through its cellular connection.
HTML
The behind-the-scenes code that tells a browser how a webpage should be structured — headings here, paragraphs there, images in this spot.
HTTP 404
The "page not found" error. The website exists, but the specific page you asked for does not — maybe the address is mistyped or the page was moved.
HTTP 500
A "something broke on the website's end" error. Nothing is wrong with your device — the site itself has a problem. Try again in a few minutes.
HTTP 503
A "website temporarily unavailable" error, usually because it is overloaded or being worked on. Try again later.
HTTP/HTTPS
The rules browsers and websites follow to send data back and forth. HTTPS is the secure, encrypted version — look for the padlock in the address bar.
I
Icon
The little picture on your desktop or phone screen that you tap or click to open an app.
Incognito Mode
A private browsing window that does not save your history, cookies, or what you typed — but it does not hide you from your employer, school, or internet provider.
IP Address
A unique number assigned to each device on a network — like a home address so data knows where to go.
ISP
Internet Service Provider — the company that brings the internet into your home. Comcast, Xfinity, AT&T, and Verizon are common ISPs.
J
JavaScript
A programming language that powers the interactive bits of websites — pop-ups, animations, forms that check your answers as you type.
JPEG
A very common photo file format (.jpg or .jpeg). Great for photos because it makes file sizes small, at a tiny cost to quality.
K
Kernel
The deepest, most important part of an operating system. It manages the hardware and lets everything else run. You never interact with it directly.
Keyboard Shortcut
Pressing a combination of keys to do something faster than clicking — like Ctrl+C to copy or Ctrl+V to paste.
Keylogger
Sneaky software that secretly records every key you type — often used by criminals to steal passwords and bank details.
L
LAN
Local Area Network — the network inside a single home, office, or building that connects your devices to each other and to the internet.
Latency
The tiny delay between asking for something online and getting a response. Lower is better — high latency feels like "lag".
Link
Clickable text or an image that sends you to another webpage. Hovering over one shows you where it actually goes — worth checking before you click.
Linux
A free, open-source operating system family. It runs most of the internet's servers and many smart devices behind the scenes.
Login
The step where you prove who you are to use an account — usually a username and password.
M
MAC Address
A permanent ID built into every piece of network hardware. Your Wi-Fi router uses it to tell your devices apart. Not the same thing as a Mac computer.
Malware
A catch-all word for any software made to harm you — viruses, spyware, ransomware, and more.
Mbps
Megabits per second — the unit used to describe internet speed. 100 Mbps is plenty for most homes; 25 Mbps is the bare minimum for streaming.
Megabyte
A unit of storage. One megabyte (MB) is a bit more than a long email with photos attached. 1,000 megabytes make a gigabyte.
Metadata
Hidden "data about data" attached to files — like when a photo was taken, what camera made it, and sometimes even where.
Migration
Moving your stuff — contacts, photos, apps, settings — from an old device or service to a new one.
Modem
The box that connects your home to your internet provider. It is often combined with a router into one unit.
Multitasking
Running several apps at once. Modern phones and computers do this smoothly, but too many open apps can still slow things down.
N
Network
Any group of devices connected together to share things — your home Wi-Fi is a network, and so is the whole internet.
NFT
Non-Fungible Token — a digital receipt stored on a public ledger that says you "own" a particular digital item, like an image or video.
Notification
A pop-up or banner from an app that wants your attention — a text, a calendar reminder, breaking news. You can turn any of them off in Settings.
O
Offline
Not connected to the internet right now. Some apps still work offline using what they already have saved.
Open Source
Software whose code is public so anyone can read it, change it, or share it. Firefox, Linux, and VLC are famous examples.
Operating System (OS)
The main software that runs your device and lets everything else run on top of it — Windows, macOS, iPhone's iOS, and Android are all operating systems.
P
Password Manager
An app that remembers all your passwords for you behind one master password. Makes strong, unique passwords for every account effortless.
A universal document file (.pdf) that looks the same on every device. Good for things that should not be easily edited, like contracts and receipts.
Permissions
The rules your device follows about what an app is allowed to access — your location, contacts, camera, microphone. You can change these anytime in Settings.
Phishing
A scam where someone pretends to be a trusted company (your bank, Amazon, the IRS) in an email or text to trick you into handing over passwords or money.
PIN
A short numeric password — usually 4 to 6 digits — often used to unlock phones and bank cards.
Ping
A quick test that measures how long it takes to reach a server and get an answer back. Low ping means a snappy connection.
Pixel
One of the tiny dots of color that make up everything on a screen. More pixels packed in means a sharper image.
Platform
A system that apps and services are built on top of — iOS is a platform, Facebook is a platform, Windows is a platform.
Plugin
A small add-on that gives a program extra abilities. Very similar to a browser extension, but for any kind of software.
Pop-up
A small window that jumps on top of whatever you were looking at. Some are useful; many are ads or scams, especially the ones that shout about "viruses".
Port
Either (1) the physical socket you plug a cable into, or (2) a numbered channel your device uses to sort different kinds of internet traffic.
Q
QR Code
A square black-and-white pattern you scan with your phone's camera. It opens a link, adds a contact, or joins a Wi-Fi network.
R
RAM
Your device's short-term memory. It holds whatever you are working on right now. More RAM means more apps can stay open without slowing down.
Ransomware
Nasty malware that locks up your files and demands payment to unlock them. Never pay — restore from a backup instead.
Reboot
Turning a device fully off and back on again. It fixes more problems than almost any other trick.
Refresh
Asking your browser or app to reload a page to get the latest version. On a desktop, press F5 or Ctrl+R.
Release
The final, polished version of software made available to the public, after alpha and beta testing.
Rendering
The work your device does to turn code and data into the actual image you see on screen — from a webpage to a 3D movie scene.
Resolution
How many pixels are in a screen or picture, usually written like 1920×1080. Higher resolution means a sharper image.
Router
The device in your home that shares one internet connection with all your Wi-Fi devices and manages the traffic between them.
S
Safe Mode
A stripped-down way of starting your computer or phone, with only the essentials. Useful for troubleshooting when something is making the device misbehave.
Sandbox
A walled-off space where an app can run without being allowed to touch the rest of your device. Keeps anything risky contained.
Screenshot
A snapshot of whatever is currently on your screen, saved as an image. Great for showing someone exactly what you're seeing.
Search Engine
A website that finds other websites for you based on what you type — Google, Bing, and DuckDuckGo are the best known.
Server
A powerful computer whose job is to send websites, videos, emails, or files to other devices that ask for them.
SIM Card
The small chip inside your phone that tells the cell network your phone number and plan. Can usually be moved to another phone to move service with it.
Smishing
Phishing by text message. "Your package could not be delivered, click here" is a classic example — always a scam.
Social Engineering
Tricking a person — rather than hacking a computer — into giving up information or doing something they should not. Most scams are really social engineering.
Software
The programs, apps, and operating systems that run on your device — anything you cannot physically touch.
Spam
Unwanted messages sent in bulk, usually by email or text. Some is just annoying ads; some is dangerous phishing.
Spoofing
Faking the "from" name of a call, text, or email to look like someone you trust. Never trust who an email says it is from — check how it is written and what it asks you to do.
Spyware
Software that secretly watches what you do — keystrokes, websites, even your microphone — and reports it back to someone else.
SSD
Solid State Drive — a fast, modern type of storage with no moving parts. Switching from an old hard drive to an SSD is the single biggest speed boost for an aging computer.
SSID
The name of a Wi-Fi network — the thing you pick from the list of networks on your phone or laptop.
Stack Trace
A list that shows the chain of steps software was doing when it crashed. Developers read it to figure out what went wrong.
Streaming
Watching or listening to something over the internet in real time without saving the whole thing to your device first — Netflix, Spotify, YouTube.
Subnet
A smaller network inside a bigger one. Your home network is a subnet inside your internet provider's network.
Sync
Keeping the same information up to date across several devices automatically — like photos that appear on your phone, tablet, and computer at the same time.
T
Task Manager
A tool that lists everything running on your computer and lets you force-close something that is stuck. On Windows, press Ctrl+Shift+Esc.
Terminal
A typing-only window where you can give your computer commands directly. Powerful, but not something most people ever need to touch.
Tor
A free network that bounces your internet traffic through several computers around the world to keep you anonymous. Used for privacy — and for the dark web.
Touchscreen
A screen you interact with by tapping, swiping, and pinching instead of using a mouse. Found on almost every phone and tablet.
Troubleshoot
The process of figuring out why something is not working by testing one thing at a time until you find the cause.
Two-Factor Authentication (2FA)
A second check, in addition to your password, to prove it is really you — usually a code texted to your phone or generated by an app.
U
Update
A new version of software that fixes bugs, patches security holes, or adds features. Ignoring updates is one of the biggest risks to your online safety.
Upload
Sending a file from your device to the internet or another device — the opposite of download.
URL
A web address — the thing you type into a browser, like https://www.teksure.com. Always check it matches what you expect before you type in a password.
USB
The standard connector for plugging things into a computer — flash drives, mice, keyboards, chargers. USB-C is the newer, smaller oval-shaped version.
V
Verification Code
A short one-time code (often six digits) sent to your phone or email to confirm it is really you logging in. Never share it, no matter who asks.
Virtual Machine
A pretend computer running inside your real one. Handy for testing risky software without putting your real device at risk.
Virus
A type of malware that spreads from file to file or device to device, often causing damage along the way.
Vishing
Phishing by voice call. Someone pretending to be Social Security, the IRS, or your bank tries to scare you into giving up money or information. Hang up.
Voice Assistant
An app that listens for commands and replies out loud — like Siri, Alexa, or Google Assistant.
VPN
Virtual Private Network — a paid service that scrambles your internet traffic and hides your location. Useful for privacy on public Wi-Fi.
W
WAN
Wide Area Network — a network that stretches across a big distance. The internet itself is the biggest WAN of all.
Webcam
The camera built into your laptop or monitor, used for video calls. A small sliding cover or piece of tape is an easy privacy upgrade.
Wi-Fi
Wireless internet inside your home or a shop, sent out by a router. Public Wi-Fi is convenient but not private — use a VPN for anything sensitive.
Widget
A small interactive box you can place on your home screen or desktop — a weather forecast, calendar, or quick calculator.
Windows
Microsoft's operating system for most personal computers. Not the same as browser windows.
X
XML
A way to store information in plain text using labeled tags. You almost never see it, but lots of apps use it behind the scenes to talk to each other.
Z
Zero-Day
A security hole in software that the people who made it don't know about yet — meaning there is no fix available yet. Very valuable to criminals, and dangerous to everyone else.
Zip File
A file (ending in .zip) that bundles several files together and shrinks them, so they're easier to email or download.