What is Content-Based Security?

I’ve heard of the buzzword, “Content-based security”, in reference to Computer Systems and networks.

What exactly is it? It’s different than traditional passwords, I suspect, but what is it and how does it work?

One version consists of network gear that refuses to pass “bad” traffic.
If an HTTP request is malformed and could have my web server… it doesn’t pass, it gets discarded.
If there’s an evil piece of javascript in a packet… it gets discarded or replaced by something harmless.

The network gear in question doesn’t actually interpret the packets in question, and is thus safe from harm, in theory and usually in real life.
There is another meaning, where content-based security is an access control system for user traffic based on user identity… not sure if that’s an acceptable definition or not.