Hectare (ha)
The hectare, or ha, is a metric area unit equal to 10,000 square meters (a square with 100-meter sides). First used in France in 1795, it is now widely used worldwide, particularly in farming, forestry, and land planning. Although it is not an official SI unit, it is permitted because it is practical for measuring fields and properties. Its simple size makes it better than the square kilometer for medium areas.
Square Yard (yd²)
The square yard, or yd², is an area unit from the imperial system. It is the area of a square with one-yard sides and equals 9 square feet or 0.836127 square meters. Used first in England, the square yard was set as a standard in the 1900s. It is still used in the US and UK, particularly for real estate, carpets, fabrics, and sports fields. While most of the world now uses square meters, the square yard is still recognized and used in certain professions.