The inch is a unit of length in the imperial unit system with the symbol in.
There are 12 inches in a foot and 3 feet in a yard. Therefore there are 36 inches in a yard. There are exactly 2.54 centimetres in an inch.
Borrowed from the Latin 'uncia' - the English word 'inch', the origination of the word came from the Old English word for 'ounce' which was related to the Roman phrase for "one twelfth".
The inch is still a commonly used unit in the UK, USA and Canada - and is also still used in the production of electronic equipment, still very evident in the measuring of monitor and screen sizing.
The yard is a unit of length in the imperial and US system and uses the symbol yd.
A yard is equal to 3 ft or 36 inches. There is 0.9144 m in a yard. There are 1760 yards in a mile.
Derived from the Old English 'gyrd' or 'gerd', the yard was first defined in the late 1600s laws of Ine of Wessex where a "yard of land" (yardland) was an old unit of tax assessment by the government.
The yard was the original standard adpoted by early English leaders and was apparently used in length by the Saxon race and represented the breadth of the chest of a man. After a relative hiatus, Queen Elizabeth reintroduced the yard as the English standard of measure, and it still survives in many 2nd generation conversations today.