I was asked a few times what is the difference between HIPS, NIPS, IPS, Application Firewall.  I did research a bit about this and started to write something. But, then I found this great article (see below at the resources) which describes everything perfect. Also read my own conclusions at the end of the article.   Introduction We are all somewhat familiar with Intrusion Prevention Systems (IPSs). But what is all this talk of Web Application Firewalls (WAFs)? What is a Web Application Firewall and how does it differ from an IPS? First, let’s take a quick look at Intrusion Prevention, its benefits and some short-comings. Then we will discuss WAFs and how they differ from and augment IPSs. Intrusion Prevention System (IPS) An IPS generally sits in-line and watches network traffic as the packets flow through it. It acts similarly to an Intrusion Detection System (IDS) by trying to match data in the packets against a signature database or detect anomalies against what is pre-defined as “normal” traffic. In addition to its IDS functionality, an IPS can do more than log and alert. It can be programmed to react to what it detects. The ability to react to the…