Transitions between sections: Particularly in longer works, it may be necessary to include transitional paragraphs that summarize for the reader the information just covered and specify the relevance of this information to the discussion in the following section.
The main difference between wheel and rim is that rim is not the whole wheel but only a part of the wheel. Key parts of the wheel are rim and disc. The hub may be also considered as a part of the wheel. The hub is wheel base with studs on which the wheel is attached to the suspension. The rim is a cylindrical wheel outer edge holding the tire on the wheel. Main function of the rim is supporting and sealing the tire to the wheel.
There are two basic types of wheel/rim systems. Vehicles that have spoke wheels have the wheels permanently (they aren't removed when the tire is changed) attached to the vehicle. Tires are mounted on rims that have no center discs. These rims slip over the spokes and are clamped to the spokes of the wheels. These wheel/rim systems are called spoke wheel/demountable rim systems. The second major system type is the disc wheel system. Here, the rim is permanently welded to a wheel with a disc in the center containing a mounting face with a bolt hole circle. This wheel is bolted onto the vehicle with studs that are inserted through holes in the hub, brake drum and wheel and fastened with lug nuts.