I'm not being a smart ***** here but this is how the two are defined:
Rims
Specifically, a rim is part of a wheel; it is the most outer edge of a wheel, and is the location where a tire is attached. The term rims has also been coined as a slang term for fancy or customized wheels on a car, but a rim does not have to look a certain way to be effective. It is used by car lovers everywhere to describe a specific type of wheel: these wheels are almost always bought as an aftermarket purchase, and they can be custom-made for a specific automobile. When used in the slang sense, rims are usually chrome, alloy, or another shiny and durable material. Not everyone refers to these specific styles as rims; some people choose to call them wheels instead, and sometimes, although technically incorrect, the term rims can be used to describe standard factory wheels on a car, sport utility vehicle, or truck.
Wheels
Another difference between rims and wheels is how they operate; a wheel is a round device that rotates to allow a vehicle or other heavy equipment to move. In the case of a car wheel, the wheel should include a rim, and a tire. To be able to rotate, wheels are connected in parallel pairs, through their center, by an axle. The rotating motion moves the vehicle forward or backward, depending on which direction the wheel rotates. The discs go between the wheel (tire and rim combination) and the hub. Think of it as a bologna sandwich. One slice of bread is the hub, the bologna is the balancer, and the other slice of bread is the wheel. They are very thin and sit flat against the hub when the wheel is mounted.