Malware
Spyware, Viruses, and Trojan Horse
Definitions
Spyware: a software that gathers information about a person or organization that can give the information to another person for their benefit.
Viruses: a small agent that acts like a sickness and spreads when it has contact with another computer, these can do many things including taking personal information and computer space.
Trojan Horse: a hacking program that provides a "backdoor" for who ever is trying to get in.
How should you avoid it?
Firewalls and antivirus software can be very helpful when you are trying to avoid malware. Why? Antivirus softwares help because they have a list of viruses that can be caused by certain websites. When you try to go to one of these certain websites they don't allow you. Firewalls also are like that. They only let you in to websites that are safe.