Socket

There are a few types of sockets that are compatible with ratchet handles, breaker bars, torque wrenches and other tools, but they have different uses. In the image below, a standard socket (left), impact socket (middle) and spark plug socket (right).

Make sure to use the correct socket type in order to avoid damage to your vehicle.

Standard sockets are for standard nuts and bolts, such as you would find securing your lights, alternator and other low-pressure parts.
More about standard sockets

Impact sockets are for use with strong and extra-tight nuts and bolts such as those that hold your wheels, shock absorbers and engine in position. Such bolts can tolerate the extra pressure of being tightened to high torque values and loosened with impact tools, lever bars and other dedicated torque-aids.
More about impact sockets

Spark plug sockets are longer and contain a gromit to aid in the removal of spark plugs from deep holes. This is a light duty task, but the length of the dedicated spark plug socket is necessary in order to reach over the length of the plug to the thread, which is located much further down.
More about spark plug sockets

A full socket set includes the ratchet handle, extension bars and a full range of sockets.