What is Intrusion Detection?
Intrusion detection is the ability to detect people trying to probe or compromise your system. Intrusion detection is divided into two main categories, host based, and network based. In simple terms, host based means that you are using a single host to monitor itself, and network based means you are using a host to monitor a complete network segment. Most home Linux users will only be concerned with host-based Intrusion Detection Systems (IDS).