A computer virus is a computer program or code that can replicate itself and spread from one computer system to another system. A computer virus has the capacity to corrupt or to delete data on your computer and it can utilize an e-mail program to spread the virus to other computer systems. In the worst case scenario, it can even delete everything on your hard disk. The purpose of it to disrupt the operation of the computer or the program.
In the same way as viruses harm peoples' bodies, computer viruses can do considerable damage to computer systems. Viruses are infections. Computer infections can come in several forms and your computer can "catch" one in several ways:
• An email virus is one type. An email virus can travel through attachments in email messages and can automatically replicate itself by mailing itself to dozens or even hundreds of people on your list of contacts found in your online address book. There are email viruses which don’t need to be double-clicked in order to install themselves as they can launch while you are simply viewing the message.