My understanding is that these kinds of planes have systems that issue prominent warnings if they are about to fly into terrain other than terrain they are supp

My understanding is that these kinds of planes have systems that issue prominent warnings if they are about to fly into terrain other than terrain they are supposed to fly into such as airport runways. Questions: how do those systems know when the terrain is a runway? Do they automatically know it, or do the pilots when approaching the airport turn the terrain warning system off?