Computer security is the process of preventing and detecting intrusions into your computer system. Prevention measures help you keep intruders from accessing any part of your computer system. Detection helps you to determine whether or not someone attempted to break into your system, whether or not they were successful, and what they may have done.

We now use computers for everything from banking and investing to shopping and communicating with others through email or chat programs. Although you may not consider your communications "top secret," you probably do not want strangers reading your e-mail, using your computer to attack other systems, send forged email from your computer, or examining personal information such as financial statements.