What is an Intrusion Detection System (IDS)?

An Intrusion Detection System (IDS) attempts to watch a network or system for incoming attacks, or for malicious or unauthorized use of network or system resources. Typically, an IDS acts as an informant, rather than a policing agent, for a network. There are several IDS's on the market, for example one of the IDS's we use is Real Secure by Internet Security Systems.