A computer virus is similar to a biological virus in that it is spread from one computer to another in a similar way that viruses spread from one person to another. Additionally, a computer virus cannot spread until it is executed. In order to be executed, a computer virus rides on top of other programs or documents, and then the harmful effects begin.

Once you have a computer virus has become 'alive' and started to infect your computer a whole host of problems can arise. Most of the problems caused by viruses are not entirely damaging to your computer, while some can be destructive in that they can destroy damage. Most of the negative effect of viruses comes in the form of the out of control reproduction, which can take up computer space.

Computer viruses are also extended to worms spread over the internet, which act in a similar fashion, but are more harmful and malicious in intent.The best solution is to get good software that will scan your computer for any Spyware, Adware and Viruses you might already have installed as well as eliminate it and protect you from further invasions.

One other thing to note is that while most viruses are targeted toward Windows Operating Systems, all operating systems, including Mac OS and Linux can be infected.

Your best protection is Anti-Virus Software that continually updates and to be careful about what you download off the internet. You only want to download from services or websites that you know to be safe.