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 mile is a unit of length in the metric system, equal to 1.60931 kilometers. It is also the basic distance unit used throughout the United States of America and many countries of the world. The word “mile” comes from the Latin word for “a thousand paces,” although its actual origins are still debated by scholars. The Romans used it to measure distances from one water source or naval station to another. Over time, other units were also derived from the mile, including the yard, league, foot and inch. Today, various definitions of the mile exist, but it is most commonly defined as 3,280 feet or 1.609 kilometers.