Chess Opening Theory/1. e4/1...c6/2. Nc3

Caro-Kann Defence, Two Knights Variation
Instead of committing to a pawn to d4 move, White is attempting a more cautious approach by placing a knight on c3 first. The vast majority of players play /2...d5/ with white usually continuing with 3. Nf3. By placing the knight first, White is giving itself more flexibility over when to commit to a d pawn advance.