The yard is a unit of measurement, equal to three feet, 36 inches, or one one-hundredth of a football field. It is slightly smaller than the metric measurement of a meter (specifically 0.914 meters). Just as the "foot" was originally the length of a man's foot, the "yard" was originally the length of a man's yard, or the distance from the tip of one outstretched finger to the one on his other hand.
Yards are typically measured with a yardstick.