The Benoni Defence can be divided into two main structures, which are very different in concept: the Modern Benoni, 1.d4 Nf6 2.c4 c5 3.d5 e6 4.Nc3 exd5 5.cxd5 d6 and the Czech (or Old) Benoni 1.d4 Nf6 2.c4 c5 3.d5 e5 which is much less dynamic.
This book deals with both systems. Black can reach the main line of the Modern Benoni in either of two ways: 2...c5 3.d5 e6, or 2...e6 3.Nf3 c5 4.d5 ?xd5.
Dreev shows the best move orders which allow White to reach the same main tabia with e4,Bd3,h3.
Dreev: "In this book I have analysed all Black’s possible responses that deserve attention and in a great many variations I have suggested promising possibilities for White which are new to theory."