Glossary
Glossary of everyday technology terms
Short definitions of the terms used across the explainers, in alphabetical order. Each one points to the explainer that covers it in more depth.
- Authenticator app
- An app that shows a short code which changes every few seconds, used as a second factor when signing in. It does not depend on your phone number, but the code can still be typed into a fake site. More in Multi-factor authentication.
- Backup
- A second copy of files kept somewhere other than the device they normally live on, so they can be restored after loss, damage or ransomware. More in Backups.
- Caller ID spoofing
- Deliberately falsifying the number or name shown when a call arrives, often to look like a local number or a known organisation. More in Phishing and scams.
- Domain Name System (DNS)
- The distributed system that turns names such as a website address into the numeric addresses networks use. Responsibility for names is split across many servers in a hierarchy. More in How the internet reaches your device.
- Download and upload speed
- How fast data reaches you (download) and how fast you send it (upload), usually measured in megabits per second (Mbps). Video calls use both. More in How the internet reaches your device.
- Encryption
- Scrambling data so that only someone with the right key can read it. Used for connections to websites, for Wi-Fi and for stored files. More in How the internet reaches your device.
- End of support
- The point after which a maker stops releasing security fixes for a device or program. It keeps working, but new weaknesses stay unfixed. More in Software updates.
- Firmware
- Software built into a device such as a router, camera or printer. It needs updating like any other software. More in Software updates.
- HTTPS and the padlock
- A web address starting with https means the connection to that site is encrypted. It says the line is private, not that the site is honest. More in How the internet reaches your device.
- IP address
- The numeric address used to deliver data to a device on a network. IPv4 addresses are 32-bit numbers; IPv6 addresses are 128-bit. More in How the internet reaches your device.
- Malware
- Software designed to harm a device or its user, for example by stealing information, spying, or locking files. More in Software updates.
- Multi-factor authentication (MFA)
- Signing in with two or more different kinds of evidence: something you know, something you have, or something you are. Also called two-factor authentication or 2-step verification. More in Multi-factor authentication.
- Packet
- A small unit of data with a header that includes where it came from and where it is going. Larger files travel as many packets. More in How the internet reaches your device.
- Passkey
- A sign-in credential based on public key cryptography. The private key stays on your device and is unlocked with your fingerprint, face or PIN; the website holds only the public key. Passkeys resist phishing. More in Passwords and passkeys.
- Password manager
- An app, or a feature of a browser or device, that stores your passwords so each account can have a long, unique one. More in Passwords and passkeys.
- Patch
- A piece of software released to fix a problem in a product, often a security weakness. Updates frequently contain patches. More in Software updates.
- Phishing
- A message that pretends to come from a trusted source to trick someone into revealing information, paying, or installing something harmful. By text it is sometimes called smishing, and by phone, vishing. More in Phishing and scams.
- Phishing-resistant MFA
- A second factor that checks which website is asking before it responds, so a look-alike site gets nothing useful. Security keys and passkeys based on the FIDO standards work this way. More in Multi-factor authentication.
- Push prompt
- A notification sent to an app asking you to approve a sign-in. A prompt you did not expect is a warning sign; deny it. More in Multi-factor authentication.
- Ransomware
- Malware that encrypts files and demands payment to unlock them. Offline backups that have been tested are the main way to recover without paying. More in Backups.
- Resolver
- The service that looks up domain names on your device's behalf, often run by your internet provider or set in your router, and remembers answers for a while. More in How the internet reaches your device.
- Router
- The box that directs traffic between the devices in your home and the internet. It often includes the modem and the Wi-Fi access point, and it has its own settings and firmware. More in How the internet reaches your device.
- Security key
- A small physical device that proves your identity using cryptography when you sign in. It is a phishing-resistant second factor. More in Multi-factor authentication.
- Social engineering
- Manipulating people, rather than breaking into systems, to get access, information or money. Phishing is the most common form. More in Phishing and scams.
- TLS (Transport Layer Security)
- The protocol that encrypts connections between your browser and a website, designed to prevent eavesdropping, tampering and forgery. It is what puts the s in https. More in How the internet reaches your device.
- WPA2 and WPA3
- Security standards that encrypt Wi-Fi traffic. WPA3 is the newer; WPA2 is the fallback when a device does not support WPA3. More in How the internet reaches your device.