The big idea

What the Benoni Defence is really about.

A fighting, asymmetrical defence for players who hate dull positions. Black willingly hands White more space in the centre, accepting a cramped but spring-loaded position. In return Black gets a queenside pawn majority, a powerful fianchettoed bishop, and the dynamic breaks ...c5 (already played) and ...b5 to generate counterplay.

White's plan: Use the extra central space: keep the d5-pawn as a wedge, develop harmoniously, and try to clamp down on Black's queenside before the counterplay gets rolling.
Black's plan: Embrace the imbalance: fianchetto on g7, push the queenside majority with ...a6 and ...b5, and use the half-open e-file and active pieces to make the cramped position bite back.

After 1.d4 Nf6 2.c4 c5 3.d5 e6

The Modern Benoni trades a space disadvantage for dynamism: a queenside pawn majority and the ...b5 break, the fianchettoed bishop on g7, and pressure down the half-open e-file.

Black is cramped in the Benoni. Where does the counterplay come from?

Answer the question to keep going!