An electric generator converts energy of motion into electrical energy. The energy of motion can be obtained through the motion produced by an internal combustion engine, or through mechanical means, such as by the use of a crank.
A generator does not produce electricity; it merely helps to move the electrical charge in the conductor, which in this case is the coil of wire. The electric generator works on the principle of electromagnetic induction. When a coil of wire is rotated in the presence of a magnetic field, electric current is generated in the coil of wire. This current is then taken out through the use of a commutator. This produces DC, or “Direct Current.” When alternators are used, it leads to the generation of AC, or “Alternate Current.”