How many types of hitches are there for electrical appliances in a car? Each give an example

There are two kinds of electrical appliances on the car iron way, in the original no car silicon rectifier generator before, the generator is a DC generator, with a positive iron, like the old liberation of the transporter CA-10b, the original of the Soviet Union's Gaz 51 transporter, Gaz 69 cross-country sedan, etc., since China's use of automotive silicon rectifier generator, such as the liberation of the 1091 automobile, etc., the use of the unification of the negative iron Form, until now, the positive pole iron form of automotive power distribution gradually eliminated.