Chess Opening Theory/1. d4/1...Nf6/2. c4/2...g6/3. Nc3/3...Bg7/4. e4/4...d6/5. Nf3/5...O-O

= King's Indian Defence =

Classical
This position is part of the Classical King's Indian Defence. White has an expansive pawn trio which Black is planning on attacking. White must brace himself because Black's counteroffensive in the centre of the board is about to start with ...e5.

6.Be2 is simply allowing White the opportunity to allow his King to get to safety (and stop the ...Bg4 pin on the knight) before Black begins his counteroffensive in the middle of the board. This move is played the vast majority of the time.

6.h3 is more passive move that stops ...Bg4 from happening but without allowing a kingside castle. This leaves the King slightly more vulnerable.

Theory table
'''1. d4 Nf6 2. c4 g6 3. Nc3 Bg7 4. e4 d6 5. Nf3 O-O'''