The Caro-Kann Defense

The Caro-Kann can only be played against e4 and it begins with c6. The point of this opening from Black's perspective is to put a pawn in the center but have it protected by another pawn - what we call a building-block opening. So, when White puts two pawns in the center we play d5.

(Rozman 2023, 309 chap.11 part.2)

References:

Rozman, Levy. 2023. How to Win at Chess: The Ultimate Guide for Beginners and beyond. Ten Speed Press.