Denial Of Service (DoS)
DoS is an attack designed to render a computer or network incapable of providing normal services. The most common DoS attacks will target the computer's network bandwidth or connectivity. Bandwidth attacks flood the network with such a high volume of traffic, that all available network resources are consumed and legitimate user requests can not get through. Connectivity attacks flood a computer with such a high volume of connection requests, that all available operating system resources are consumed, and the computer can no longer process legitimate user requests. The high-profile attacks of the week of February 6th, 2000 were primarily bandwidth attacks, and all of the targets were high-profile internet web sites. A complete description of Denial of Service attacks is available from CERT.