IDS

IDS stands for "Instrusion Detection System."

An IDS is responsible for identifying internet traffic that doesn't belong on a specific network. If it finds out that someone is accessing a place on the web that it isn't supposed to, the IDS will report that vulnerability to the owners of the application.

Another important characteristic of IDPs is that they don't actually block the offending traffic. Instead, all they do is analyze the malicious traffic and make sure that you know about it.

For more information, see Intrusion Detection System.