What is a mating net?

Looking at my Tactics stats and there is a section called mating net! What does this mean?

It's when you surround the king, cutting off all means of escape before moving in for the kill.

The last couple of moves in this game are a good example of a mating net.  White falls for it by responding to 31...Rf4+ with 32.Kh5?? when Black plays 32...Ra6 defending his h-pawn and creating an inescapable mating net.

https://www.chess.com/echess/game?id=133600416

That is what cavemen used to find wives.

Thanks 

hilarious 

I have heard this term used in what appeared to be very technical sense by experts, so I'm going to assume that there is a precise definition. It's not just when the King is surrounded and there's a vague threat of Checkmate looming, (although it's probably used in this way as well).

My definition of a Mating Net:

A position where Checkmate is guaranteed with perfect play by the attacking player.