A HIDS (host-based intrusion detection system) runs on a single computer to alert about attacks to thatone host. For example, a HIDS might detect an attempt to exploit an insecure application running on aserver or repeated attempts to log on to the server. A NIDS (network-based intrusion detection system) protects a network and is usually situated at theedge of the network or in a network' s protective perimeter, known as the DMZ, or demilitarized zone.Here, it can detect many types of suspicious traffic patterns, including those typical of denial-of-serviceor smurf attacks, for example.