Electric Motors

An electric motor converts electrical energy into mechanical energy. Most electric motors operate through the interaction between an electric motor's magnetic fields to generate force in the motor. Electric motors can be utilized in numerous applications such as machine tools, industrial fans, pumps, watches, generators, household appliances, power tools as well as many others.
There are many different types of electric motors, this is a graph that shows the different kinds:

Major Categories

by

Type of Motor Commutation

Self-Commutated			Externally Commutated
Mechanical- Commutator Motors		Electronic- Commutator (EC) Motors	Asynchronous Machines	Synchronous Machines
AC	DC	AC	AC
* Universal motor (AC commutator series motoror AC/DC motor) * Repulsion motor	Electrically excited DC motor: * Separately excited * Series * Shunt * Compound PM DC motor	With PM rotor: * BLDC motor With ferromagnetic rotor: * SRM	Three-phase motors: * SCIM * WRIM AC motors: * Capacitor * Resistance * Split * Shaded-pole	Three-phase motors: * WRSM * PMSM or BLAC motor - IPMSM - SPMSM * Hybrid AC motors: * Permanent-split capacitor * Hysteresis * Stepper * SyRM * SyRM-PM hybrid
Simple electronics	Rectifier, linear transistor(s) or DC chopper	More elaborate electronics	Most elaborate electronics (VFD), when provided

 There are also many different components that are required in order to construct and electric motor:

Rotor: In an electric motor the moving part is the rotor which turns the shaft to deliver the mechanical power. The rotor usually has conductors laid into it which carry currents that interact with the magnetic field of the stator to generate the forces that turn the shaft. This is an example of a rotor and.

Stator:The stationary part is the stator, usually has either windings or permanent magnets. The stator is the stationary part of the motor’s electromagnetic circuit. The stator core is made up of many thin metal sheets, called laminations. Laminations are used to reduce energy loses that would result if a solid core were used.
Windings: Windings are wires that are laid in coils, usually wrapped around a laminated soft iron magnetic core so as to form magnetic poles when energized with current.
Commutator: A commutator is a mechanism used to switch the input of certain AC and DC machines consisting of slip ring segments insulated from each other and from the electric motor's shaft. The motor's armature current is supplied through the stationary brushes in contact with the revolving commutator, which causes required current reversal and applies power to the machine in an optimal manner as the rotor rotates from pole to pole. This diagram shows how a commutator operates:

Source: http://www.seaperch.org/electric_motors