Model Game - Space Advantage In The Endgame

An excellent game played over the weekend in the Russian Higher League.  Black had a slight initiative for most of the game but was unable to break white's pawn structure.  As pieces came off the board, would it matter? ... I think the answer is yes.  White played very well.  

I've thrown in a few notes in an effort to explain the winning procedure white used in this game.  Keep in mind, though, that this game interested me so much because I am often unable to convert positions where all I have is a little extra space.