Cyber-security glossary

2FA (two-factor authentication)

Logging in to an account in two steps: something you know (your password) and something you have (a code on your phone or a security key).

Adware

A program that shows unwanted adverts, often installed together with “free” apps.

Antivirus

Software that detects, blocks and removes harmful programs from your device.

Backup

A copy of your important files kept somewhere else, so you can get them back if they are lost or encrypted.

Bot / Botnet

A bot is a program that works automatically. A botnet is a network of infected computers controlled by an attacker.

Cookies

Small files that websites save in your browser to remember your preferences or to track your activity.

Cyberbullying

Insulting, threatening, leaving out or humiliating someone through the internet, messages or social media.

DDoS

An attack that floods a website or service with traffic from many devices at once until it goes down.

Deepfake

A video, photo or voice faked with artificial intelligence so that it looks or sounds real.

Digital footprint

Everything you leave behind online: posts, comments, photos, searches. It often stays there for ever.

Encryption

Turning data into unreadable code that only someone with the key can unlock.

Firewall

A “protective wall” that checks and blocks suspicious incoming and outgoing network connections.

Grooming

When an adult wins a child's trust online in order to abuse them. Warning signs: asking for secrecy and for photos.

Hacker

A person who finds weaknesses in systems. “Ethical hackers” do it with permission so the weaknesses can be fixed; criminals do it for their own gain.

HTTPS

The secure version of HTTP: the connection between you and the website is encrypted. It does not guarantee that the website is honest.

Keylogger

A program that secretly records every key you press, including your passwords.

Malware

A general name for any harmful software: viruses, worms, trojans, ransomware, spyware.

Man-in-the-middle (MITM)

An attack where someone “sits in the middle” of your communication and reads or changes it.

Password manager

An app that creates and safely stores a different password for every account.

Patch / Update

A change to software that fixes bugs and closes security holes.

Pharming

Being redirected to a fake website even when you type the address correctly, by tampering with DNS or the router.

Phishing

Fake messages (email, text, social media) that pretend to be from someone you trust in order to steal your data.

Public Wi-Fi

An open wireless network (café, airport). Convenient, but risky for sensitive accounts.

Ransomware

Malware that encrypts your files and demands a payment (a ransom) to unlock them.

Sextortion

Blackmail using intimate photos or videos. Don't pay and don't send anything more — keep the evidence and tell an adult and the police.

Smishing

Phishing by text message (SMS).

Social engineering

Manipulating people (with fear, urgency or curiosity) into giving away information or doing something harmful.

Spam

Unwanted messages sent in bulk, often adverts or scams.

Spyware

A program that secretly spies on your activity and sends the data to someone else.

Trojan

Malware disguised as a useful program (e.g. a free game) that opens the door to an attacker.

Vishing

Phishing by phone call (voice phishing), e.g. someone claiming to be from your bank.

VPN

Virtual private network: it creates an encrypted tunnel for your internet traffic, useful on public Wi-Fi.

Worm

Malware that spreads by itself from one computer to another over a network, without the user doing anything.

Zero-day

A weakness the manufacturer doesn't know about yet, so there is no update to fix it.