Basic Knowledge on Micro Motors (Part 1)

The most common micro DC motors are including gear motors , stepper motors and servo DC servo motors. Please see below for some knowledge on micro motors for beginners. 
Motors are invented based on electromagnetic induction means. It's an electromagnetic instrument to achieve the conversion or transfer of electric energy . In the motor circuit, motors are indicated by the letter "M" (the old standard with a "D"). Its main role is to produce drive torque or electrical power for a variety of mechanical. 
Standard Motors
Standard Motors are the most common type. They are normally applied to electric toys, razors, etc. The speed of the motors are often excessively fast and the torque is often quite small. Each motor normally has only two pins. When the positive and negative terminals of batteries are connected, the two pins will start to turn. If the positive and negative terminals of batteries are attached to the two opposite pin, the motor will be reversed.
Gearbox motor
Gearboxes are attached to gearbox motors to reduce the speed and increase the torque. They are more widely applied.
Stepper motor
Stepper motors send electrical impulse signals into angular displacement or linear displacement of the open-loop. When not overloaded, the motor speed and stopping location only depend on the frequency and number of the pulse signal, without being affected by changes in the load. When the stepping driver receives a pulse signal, it will drive a stepper motor setting the direction of rotation to a fixed angle, which is referred as a "step angle". It is based on a fixed rotation angle and step by step operation. By controlling the number of pulses to control the amount of angular displacement, so as to achieve accurate positioning purposes. At the same time, by controlling the pulse frequency,  the motor rotation speed and acceleration speed are controlled, so that the speed of the motor can be adjusted .