Help me understand this move (R+B vs. R + N, w/ pawns on one side)

How would you explain the move 32.g4 in the following game?

I heard recently someone saying that top level games tend to end up with pawns on one side of the board and I have seen several of these kinds of pawn moves lately that I think can be difficult for most players to understand unless someone explains them for us. Here is another one, although perhaps not entirely relevant to this post but a nice one nevertheless: https://www.chess.com/forum/view/general/carlsen-signature-moves

That brings me to a second question of whether there are any good resources of how to handle situations with pawns on one side with different piece configurations? Are there any endgame books in particular that deal specifically with this scenario?

Thank you!

Thank you Optimissed.

I am still finding it difficult to grasp the heart of the matter here.

Would it be correct to say that in most circumstances Nimzowitsch "candidates first" principle (i.e. pushing e4 first) would be correct, but in the above case with rooks still on the board the issue is that the defender gets access to side-checks after the e- and f-pawn moves. Therefore, he starts by first advancing his g- and h-pawns to keep his king safe from side-checks? Is this the reason that h2-h4 and g2-g4 are desirable and if given the chance Black would prevent it with ...h7-h5?

Example variation of advancing the e- and f-pawns first:

I am not sure my theory completely holds up.

If I remove the rooks from the board as in the below position and keep everything else the same, the computer still likes 32.g4. But now it also thinks 32.e4 is fine for White and it does not suggest 32...h5 in response for Black.

I have read that in this position (without the bishop or knight, rooks and pawns only) that if white can play g4 before black plays....h5, it will double his winning chances.

Forget where I read that exactly. Was from a titled player I know. 

Reason being...h5 will force white to trade more pawns. Making the draw easier.

Sorry Opt.

I only read the OP. Didnt see what you wrote beneath it.

If anyone know where it has been discussed I would love to know.

I want to say Concise Chess Endings, by Neil McDonald.

But I may be wrong.

I read something similar in Korchnois book Practical Rook Endings but its probably in many other rook endgame books mentioned as well

Without minor pieces, Black's drawing technique in rook endgames 4 vs 3 pawns on one wing is to place his pawns on g6 and h5.

If White is able to split Blacks pawns and reach e + f + g vs f + h pawn (as in the game), he is winning.

Fantastic, thank you so much. I will order Korchnoi's book right away!

Thanks, will definately have a look at that book.

This one is actually pretty clear to me, 32. g4 is a prophylactic move preventing both h5 and f5.  White wants to advance his pawns, but he also wants to leave the black bishop short on targets.  It means black can now only exchange pawns on light colored squares, and that white can force him to do so (as we saw on move 36).  With the isolated pawns at that point, the position is nearly hopeless for black, the pawn ending was trivially won for white.

Suleman gambit

One advantage of the f7-g6-h5 chain for Black is that White cannot advance his king side pawns without accepting some pawn exchanges R+p vs R is a lot easier to draw than R+2p vs R+p, whish is easier to draw than R+3p vs R+2p, etc.