Holes

I think I just learned what a hole is.  It's a spot that can't be attacked any longer by enemy pawns - but it may be being attacked by another piece or might not be.  Is that right?

And a hole is a good place to put one of your minor or major pieces, especially knights?  Why is that? 

"Why is that? "

"It's a spot that can't be attacked any longer by enemy pawns."

They're also commonly called weak squares.

What is a hole? It’s a square in your half of the board that you can’t protect with a pawn.

(p. vi)
HOLE: A square in either side's camp, usually on the third rank,
that can no longer be protected by
a pawn. Usually a weakness in the
opening and middlegame.

Keene, Raymond, Edmar Mednis, Jack Peters, Julio Kaplan, and Andy Soltis. 1980. Caro-Kann Defense. Great Neck, N.Y.: R.H.M. Press.

(p. 122)
Hole   A weakness, usually a square on a player's third or fourth
rank, that cannot be defended by a pawn and is therefore ideal for
occupation by enemy pieces.

Pandolfini, Bruce. 1995. Chess Thinking. New York: Simon & Schuster.

(p. 302)
HOLE (n.)   A weakness, usually a square on one's 3rd rank
which is incapable of being defended by a pawn.

Pandolfini, Bruce. 1988. Pandolfini's Endgame Course. New York, New York: Fireside.

Riddle me this. What gets bigger the more you take away from it?

I THINK YOU BETTER EXAMINE THAT HOLE OF YOURS MORE CLOSELY PAL TO MAKE SURE YOU KNOW WHAT A HOLE LOOKS LIKE!