I may end up messing up this move order, but i have no idea what is going on in this line and was hoping someone might shed a little light on the subject for me.  Questions are in the annotations ... Ozzie?

The extended h-pawn is used to force Black's very strong bishop off the board, basically. It does afford a bit of extra kingside space to the point where White has quite a bind there, but one of the perks of the main-line Caro-Kann (in this case, I've known this as the Capablanca Variation) is that Black will endure and make the h-pawn a target in the endgame.

The h5 pawn gained space for free, as Black had to waste time with ...h6 and ...Bh7 to avoid getting trapped or at least seriously inconvenienced.  It won't become a target for a long time, if at all, as Black has far more pressing concerns to deal with:  development and castling, which will certainly be safer on the Queenside.

The main reason for its popularity, though, is that other ideas don't put much pressure on the Black position, which is quite solid with no weaknesses, whereas the h-pawn push gains a lead in development.  White has two solid development tempi in his developed Knight and Queen, is ready to castle after one more developing move on either side of the board, and has the only pawn occupying the center at d4. 

True, it is Black's move so he immediately makes up one tempo, but he is still three or more moves away from castling, and the best squares for his Bf8, Nb8, and Queen are not so clear.  His position remains positionally strong, but he must navigate the next few moves with care.

Still, this is about White's best chance to press for advantage in this line.

thanks for the responses