A meter (m) is the base unit of length in the International System of Units (SI), which is the modern metric system used for scientific and everyday measurements in most countries around the world. The meter is defined as the length of the path traveled by light in a vacuum during a time interval of 1/299,792,458 of a second.
In more practical terms, a meter is approximately equal to:
Meters are commonly used for measuring various lengths and distances, including the dimensions of objects, the length of rooms or buildings, and distances between locations on Earth. It is a versatile unit of measurement that is widely used in science, engineering, construction, and everyday life.
A chain is a unit of length used in some older systems of measurement, particularly in surveying and land measurement. In the United States, one chain is equal to 66 feet or 22 yards. Internationally, it's defined as exactly 20.1168 meters.
Chains were historically used for measuring large plots of land and for surveying purposes, often in agriculture and real estate. However, the use of the chain as a standard unit of measurement has largely been replaced by the more modern and standardized metric and imperial systems, which use units like meters, feet, and yards.
The term "chain" comes from the practice of physically measuring land using a chain made of linked metal bars or wire. Each chain was typically 66 feet long, and surveyors would lay out chains end to end to measure distances across large areas. Today, modern surveying equipment such as electronic distance measuring devices (EDMs) and GPS technology have largely replaced the use of physical chains in land surveying.