Length

Length is a measure of distance. The cited article explains that in the International System of Quantities length is a quantity with dimension distance, that in most systems of measurement a base unit for length is chosen from which all other units are derived, and that in the International System of Units the base unit for length is the metre. It notes that length is commonly understood to mean the most extended dimension of a fixed object, though this is not always the case, and that various terms for the length of a fixed object are used, including height, width, breadth and depth. Units such as the metre, the foot and the mile are grouped under this quantity.