WHAT IS DENIAL OF SERVICE ATTACK ?

A denial of sevice attack is a malicious attack against a computer system. Most denial of service attacks are attacks that cause a computer to work very hard so that it cannot perform any of its normal tasks. The intent with a denial of service attack is either to harass of to actually destory data.

Many denial of service attacks just take advantage of existing services and thus the only defense against many attacks is to simply turn the service off. Some exploits, however, take advantage of bugs in a program and for some atacks there are patches and fixes avaiable for downloading.