Imagine a virus like a cold, but for computers. People create viruses for many reasons. Some want to break things on purpose, like damaging software or even the computer itself. Others might want to steal information. A famous virus called CIH or Chernobyl could ruin computers running Windows 95 by messing up their data and, in bad cases, breaking the computer so badly it needed new parts. Then there's Stuxnet, a super-smart virus designed to sabotage an Iranian factory by making machines destroy themselves. And believe it or not, some viruses were made just for laughs, like the Christmas virus that spread holiday cheer but also caused big problems by sending itself to too many people and crashing computer systems.

Think of worms as sneaky creatures that spread by themselves to steal data or cause trouble online, like slowing down websites so much that they stop working. The Mirai worm is a notorious one that took over lots of internet-connected gadgets and used them to attack big websites like Twitter and Netflix, making them hard to use for a while.

This is like a kidnapper for your data. Hackers use ransomware to lock up your important files and then ask for money to unlock them. Sometimes they do it just to cause trouble and make someone look bad.

Spyware is like someone spying over your shoulder while you type. It's sneaky software that watches what you type, like passwords or bank details, so hackers can steal from you or plan bigger attacks.

Named after the famous Trojan horse, these are tricky programs that pretend to be harmless but are actually harmful. They can steal your information, spread ransomware, or even take over your device to attack others online.