入侵检测是指对入侵行为的发现、报警和响应，它通过对计算机网络或计算机系统中的若干关键点收集信息并对其进行分析，从中发现网络或系统中是否有违反安全策略的行为和被攻击的迹象。入侵检测系统(intrusion detection system,IDS)是完成入侵检测功能的硬件的软件和集合。-Intrusion detection is refers to intrusion detection, alarm and response, it through the computer network or computer system some key points in gathering information and carries on the analysis, found in the network or system whether there is a violation of security policy and the signs of being attacked. Intrusion detection system (intrusion detection system, IDS) is a complete set of software, and intrusion detection function of the hardware.