Stepper motors and servo drives are often used in unison, such as in factories where robots are used. Essentially, a stepper motors is type of DC motor that moves in a given number of individual steps. Each will be fitted with multiple coils that are arranged in groups that represent each phase of the motor's operation. It is by sending power to each of these phases in a given sequence that the motor is able to rotate. With some controlling software, a stepping motor can achieve a very level of precision. Sometimes this is used to precisely locate the position of each step, but it is also used to allow for the fine tuning of the motor's speed in different applications. When used with a servo drive, a stepper motor can achieve great accuracy. These devices are basically electrical amplifiers which can be used to power direct current and hybrid stepper motors and other types of servomechanisms. When they receive a signal, they send more or less power to their respective mechanisms as a result. In proportion with the input signal, the output can be used to control the position or speed of a stepper motor, as required.