1. Viruses: A virus is a malicious code or program that can replicate itself and spread from one computer to another, often without the user’s knowledge or consent.

2. Worms: A worm is a malicious program that uses computer networks and security loopholes to replicate itself. Unlike a virus, it does not need to attach itself to a host file or program.

3. Trojan Horses: A Trojan horse is a type of malicious code that appears to be legitimate software but is actually a malicious program that can damage or gain access to a user’s system.

4. Logic Bombs: A logic bomb is a piece of malicious code designed to cause damage to a system when certain conditions are met.

5. Backdoors: A backdoor is a piece of malicious code that allows attackers to gain access to a computer system.

6. Rootkits: A rootkit is a type of malicious code that allows attackers to gain administrator-level access to a computer system.

7. Spyware: Spyware is a type of malicious code that is designed to spy on a user’s activities, often by logging keystrokes or collecting other sensitive information.

2 Factor Authentication (also known as 2FA) is an extra layer of security used to ensure that a user is who they say they are when logging into an account or website. It requires the user to provide two different forms of authentication, usually a combination of something they know (e.g. a password) and something they have (e.g. a token or smartphone). This makes it more difficult for malicious actors to gain access to an account, as they need to have both the password and physical access to the token or smartphone.

A computer is a machine that can store, process, and output information. It can perform complex calculations and tasks quickly and efficiently. Computers can be used for a variety of purposes, from playing games and creating documents to managing business operations and controlling industrial processes.