A virus is a type of malicious software designed to spread from one computer to another and cause harm. It attaches itself to legitimate programs or files and can execute when those programs or files are run.
Once activated, a virus can:
1. **Corrupt Files**: It can damage or delete files on your computer.
2. **Steal Information**: It might gather sensitive data like passwords or personal information.
3. **Slow Down Performance**: It can make your system run slowly by consuming resources or causing errors.
4. **Spread to Other Computers**: It can replicate and spread through networks or email attachments.
5. **Cause System Failures**: It might cause crashes or system instability.
Protecting your computer involves using updated antivirus software, avoiding suspicious attachments or links, and keeping your operating system and applications current.