A centimeter is a unit of length that is one hundredth of a meter. It’s the equivalent of a quarter inch, or just under three millimeters. Centimeters are used in many areas of science and engineering, including astronomy, geology, archaeology and measuring objects like car engines and medical implants. They’re also sometimes used in everyday life to measure things like the width of a door or the distance between two points.

The yard is the traditional length unit of linear measure. It is traditionally equivalent to 0.9144 meters, though it has been varied between 9 and 12 feet in recent times. The yard was first conceptualized by fifth-century BC Egyptians and was standardized as 9 feet in 1795 by the French military engineer General Hoche. During the American Revolutionary War, the Continental Army was unimpressed with various proposals for a new foot measuring system and instead adopted the British yard as their standard. The use of the yard spread rapidly throughout the world after that due to its international compatibility. Today, most countries use either the metric system or a variant of it, and there are few remaining areas where yards are used; Africa mostly uses meters, India uses centimeters, parts of Asia use traditional units like li and fen.