Types of fuses include Type T, Type S and Type W fuses. These fuses have two base types: an Edison Base, which is reserved for Type T and Type W fuses, and the Rejection Base for Type S fuses.
The Type T works with the fuse boxes of older homes, and the fuse base also resembles the base of a light bulb. The Rejection Base of Type S has two parts; one is the fuse and the other is an adapter that connects to an Edison socket. The adapter base has different threads to prevent mixing different amps. For example, a person couldn't connect a 20-amp fuse to a 15-amp circuit. Type W fuses are considered obsolete. Type W is meant for power circuits and lighting sources that don't rely on electric motors.