What is the yard ?

Source: en.wikipedia.org

" The yard is an English unit of length, in both the British imperial and US customary systems of measurement, that comprises 3 feet or 36 inches. Since 1959 it is by international agreement standardized as exactly 0.9144 meter. A distance of 1,760 yards is equal to 1 mile.
The origin of the yard measure is uncertain. Both the Romans and the Welsh used multiples of a shorter foot, but (...) "