Virus

Virus is a program that, without the user’s permission or awareness, copies itself into other files when executed. It can be copied to other programs, data files or hard drive. When it has copyied itself into the files of the system it is customary to say that the computer is infected. A virus may be relatively harmless, stealing processing power, disk space, access to private data, destroy data and/or display messages with, more or less, humorous messages.