The L293D is a dual-channel H-Bridge motor driver capable of driving a pair of DC motors or single stepper motor.
As the shield comes with two L293D motor driver chipsets, that means it can individually drive up to four DC motors making it ideal for building four-wheel robot platforms.
The shield offers total 4 H-Bridges and each H-bridge can deliver up to 0.6A to the motor.
The shield also comes with a 74HC595 shift register that extends 4 digital pins of the Arduino to the 8 direction control pins of two L293D chips. It can drive :
4 bi-directional DC motors with 8-bit speed selection(0-255)
2 stepper motors (unipolar or bipolar) with single coil, double coil, interleaved or micro-stepping.
2 servo motors