High Quality Content by WIKIPEDIA articles! A tire (in American English and Canadian English) or tyre (in Commonwealth Nations such as UK, Australia, and others) is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground. The word itself may be derived from the word "tie," which refers to the outer steel ring part of a wooden cart wheel that ties the wood segments together (see Etymology below).