What is a bastion?

What is a bastion? Do bastions win games? Any good examples...

Do you mean fortress?

https://en.wikipedia.org/wiki/Fortress_(chess) 

You need to tell me what it is, I don't really know

Maybe it is not a usual nomenclature? I gathered it has something to do with placing piece on a square where it can't be attacked by a pawn, but is not defended by a pawn because that would be an outpost (I think). Does this sounds like I made it up? 

I don't mean fortress. When I have heard this term it is usually in the opening. 

@5
Do you mean an outpost?
https://en.wikipedia.org/wiki/Outpost_(chess) 

A bastion is a piece that can only be taken by another piece, because either the pawns are off the board, or the pawns have advanced to where the pawns can't reach it anymore. 

It is slightly different than an outpost, because an outpost is a bastion that is protected by your pawn, where a bastion may or may not have protection.

Games are always won by putting your pieces on good squares and forcing your opponent to move off of good squares, so identifying good squares to put your pieces on is always a good thing(tm).   

Especially bastion knights are out standing.

Google it. Delete this NOW.

I did google it but that mostly found things unrelated to chess and the chess things were about more well known concepts. Asking here turned out to be more interesting. 

I just googled it and got this thread .