The square meter (m²) is the SI unit of area. It is defined as the area of a square whose sides are each one meter in length.
The square meter was established in the late 18th century during the French Revolution as part of the metric system. The 1795 definition was based on the Earth's meridian and later refined in 1799. In 1960, it was officially adopted as an SI unit.
Square meters are widely used in various fields, including real estate for measuring land and floor area, agriculture for crop areas, and engineering for material specifications. The unit is standard in most countries, except the United States where customary units are more common.