The Nimzo Indian is highly recommended for Black as this is a very complex chess opening that gives Black excellent chances.
This defense is classified as a closed opening. It comes to us from the great theoretician and chess grandmaster Aron Nimzowitsch who used this opening in the 20th century.
The idea is to control the center with pieces instead of pawns. The bishop on b4 pins the knight which otherwise would support a pawn going to e4. If white plays now e4 black would just capture the pawn playing Nxe4 winning a pawn as the knight is pinned. Furthermore the black bishop threatens to capture the knight and create double pawns in white's position.
As you can see black stops white to build a strong pawn formation in the center by applying pressure with pieces on center squares.
The Nimzo-Indian Defense is highly respected, very popular and one of the best chess openings for Black. It is a flexible weapon for Black against the move d4 and has been played often in world championships.
In variations in which Black captures the knight and creates a double pawn, White will have the bishop pair as compensation. If you are a beginner this opening is too difficult to grasp for you.
To avoid double pawns White can play the line 4. Qc2 but this loses time.
1. d4 Nf6 2. c4 e6 3. Nc3 Bb4 4. Qc2 d5 5. cxd5 exd5 6. Bg5 h6 7. Bh4 popular is now 7...c5 8. dxc5 g5 9. Bg3. If you are Black, surprise your opponent and play the alternative variation 7...g5 (instead of 7...c5) 8. Bg3 Ne4 9. e3 h5!?
This move will very likely upset White psychologically as Black shows unexpected aggression, avoids the popular line and White might find himself unprepared.
Now 10. f3 Nxg3 11. hxg3 looks ok for Black.