A bug is a type of destructive code or program that, when performed, duplicates itself by customizing other computer system programs and inserting its own code. When this replication is successful, the impacted areas are then said to be contaminated with a virus.
Viruses often spread out by developing a copy of themselves on a user's computer system without the user's knowledge or permission. Oftentimes, infections will be spread by e-mail attachments or by files shared on peer-to-peer networks. When a virus has contaminated a computer system, it can infect other computer systems on the same network.
Some viruses are programmed to spread themselves in a manner that could trigger serious damage to a computer system. For instance, an infection might erase files, fill a disk drive with worthless information, or corrupt system files. In many cases, a virus might even display a message or image that is developed to frighten the user.
Most viruses are relatively harmless, and only cause minor inconvenience to the user. Some infections can be really hazardous, and can cause widespread damage to computer systems. Visit This Link