What is an intrusion system? Typically, it comes in two flavors and a few different types. The basic type is either host based, network-based, or physical; the flavors are intrusion detection system (IDS) and intrusion prevention system (IPS). The goal of these types of devices are generally described as the act of detecting actions that is attempting to compromise the confidentiality, integrity, or availability of an organizations resource. If we are looking at specifics, the goal of intrusion detection is to detect or identify entities attempting to subvert current security controls; while intrusion prevention is similar to detect with the added ability to block or prevent. The key difference between the IDS and IPS is the ability to act.