One of the most important things to be aware of when playing is the motifs present in certain openings. In the Caro Kann the c file will becomes semi open for Black once the capture on d5 is recaptured with c6. Very often play will follow with some idea of getting the Rook to c8 followed by the Queen or other Rook once a lift is made. The reason this is important to understand is the because of the pressure it puts on White and the c2 pawn, which many times isn’t defended or only defended once. By being able to decide where to shift the fight early gives Black a chance to control the game and limit White’s options for aggression of their own.
In the position above there are a few things to note: The c pawn is only defended once, the White a4 Knight is under attack, the Bishop on f3 can be captured with check and there is a xray attack on the b2 pawn. White is in a bad way here. It’s White to move and they must be very careful.
The only move is to retreat the Knight to c3 where it had just come from to attack the Queen. Black is threatening to 1…Nxf3+ 2. Qxf3 Qxa4 and once the Queen moves from d3 the c2 pawn will be undefended. This isn’t an uncommon occurrence, many of my Caro games are won because of the pressure I have along the c file and White’s inability to defend.