From my understanding a closed game is a term used to describe a game in which most of each player's opening piece development takes place behind there own pawn structure. An open game is the opposite, a majority of the pieces are developed outside of the player's pawn structure. There may be a more specific definition.
closed position
Open games are tactical and feature aggressive piece development, early (pawn) tradeoffs and opening of files. Closed games are positional and focus more on the placement of pawns, closed structures and long-term tension. Generally, games with 1. e4 tend to be open and games with 1. d4 tend to be closed, though there are exceptions.

Thats what I needed to know. Another question: I seem to get into alot of closed, 1 d4 games, where all the pawns are gridlocked and nobody can do anything. Are there any good gm games I should look at to figure out how to play these positions?

Thats what I needed to know. Another question: I seem to get into alot of closed, 1 d4 games, where all the pawns are gridlocked and nobody can do anything. Are there any good gm games I should look at to figure out how to play these positions?
knights are better in closed, bishops and rooks in open, knights can jump
Thats what I needed to know. Another question: I seem to get into alot of closed, 1 d4 games, where all the pawns are gridlocked and nobody can do anything. Are there any good gm games I should look at to figure out how to play these positions?
You can go to chessgames.com and look at Queen's Pawn games.

Here's a good (strange i know) article in Wikipedia http://en.wikipedia.org/wiki/Pawn_structure that may help you devise a plan for different pawn structures. Anything with "chain", "wall', or "closed" in it would likely be a closed game.

I would like to add to this conversation that my experience has been a bit different. 1. d4 games that turn into a Queen's gambit (the 2nd most popular opening) have almost always been open games for me. Whether that is because my opponents have played the accepted variation quite a bit, I do not know, however, the queen side really opens up, I find. The Rossolimo variation of the Sicilian Defence has always led to a closed game for myself. I am playing one at the moment & I have not idea what to do, it seems gridlocked to me, so I am happy to have the knight pair, while my opponent has the bishop pair :-) I still reckon I will lose because he is rated at 1826 & I am more than 100 points lower than that.
What does that mean? what is the difference between an open and closed game