The outer hoop of a wheel to which the tire is attached.

Round part of the wheel, that the tires attach onto.

The outer hoop of a bicycle wheel. The spokes attach to the rims via spoke nipples. Rims can be either steel, aluminum, or carbon fiber.

The two metal hoops on which the tubes and tires are mounted.

Wheels ( Tricked Out episode 101)

Where the tires are mounted on. Generally, there are one-piece rims and two-piece rims. Two-piece rims consist of two cup-like halfs, which are screwed together, while one-piece rims look like a spindle and consist, as the name suggests, of only one part. Today, one-piece rims are more popular, even though some people maintain that tires are easier to change on a two-piece rims. Sometimes, these are also referred to as one-piece or two-piece wheels.

See the Toy Wonders Guide to Wheels & Rims for visual reference.