L293D is a monolithic integrated, high voltage, high current, 4-channel driver. Basically this means using this chip you can use DC motors and power supplies of up to 36 Volts, thats some pretty big motors and the chip can supply a maximum current of 600mA per channel. The L293D chip is also what's known as a type of H-Bridge. The H-Bridge is typically an electrical circuit that enables a voltage to be applied across a load in either direction to an output, e.g. motor. _x000D__x000D__x000D_Features: _x000D_2 interface for 5V Servo connected to the high-resolution dedicated timer - no jitter. _x000D_Can drive 4 DC motors or 2 stepper motors or 2 Servo. _x000D_Up to 4 bi-directional DC motors with individual 8-bit speed selection. _x000D_Up to 2 stepper motors (unipolar or bipolar) with single coil, double coil or interleaved stepping. _x000D_4 H-Bridges: per bridge provides 0.6A (1.2A peak current) with thermal protection. _x000D_Pull down resistors keep motors disabled during power-up. _x000D_Built In Reset Button. _x000D_2 external terminal power interface, for separate logic/motor supplies._x000D__x000D__x000D_Specification: _x000D_Motor voltage: 4.5V-25V _x000D_Current: 1A _x000D_PCB size: 6.7*5.3cm / 2.64*2.09in _x000D_ _x000D_Package list: _x000D_1 * Motor Drive Shield Expansion Board