There are many different kinds of motors that are used in the world today. Some of these work on an AC supply and are called AC motors. AC induction motors and AC synchronous motors are the two main types of AC motors. There are also motors that work on a DC supply, which are called DC motors. These are permanent magnet DC motors (PMDC) and brushless DC motors (BLDC). Stepper motors (unipolar and bipolar) are also essentially DC motors. Apart from these, there are also some special types of motors, such as universal motors, which can operate on AC as well as DC supply, and linear motors, which instead of producing torque produce a force in a straight-line.
Motors have a number of applications. AC induction motors are used in household applications such as fans, pumps, and compressor type of applications. AC synchronous motors are used in precise speed applications such as tape recorders, timers, clocks, etc. PMDC motors, which are also known as brushed DC motors, are used in steel rolling mills, paper machines, cranes, and for electrical propulsion. BLDC motors have a wide variety of applications and can often be used in place of brushed DC motors. Some of the places where BLDC motors are used are computer hard disks, CD players, electric and hybrid vehicles, air conditioners, wireless power tools, cooling fans used in electronics assemblies, and many industrial and robotics applications. Stepper motors are typically used in positioning systems for computer printer, scanners, CD drives, camera lenses, plotters, CNC machines, etc. Universal motors are used in household appliances such as washing machines, hair dryers, blenders, vacuum cleaners, and also in handheld power tools such as drilling machines, electrical saws, sanders, etc.