Kilogram-force
The kilogram-force (kgf or kgf), also known as kilopond (kp), is a gravitational metric unit of force. It is defined as the force exerted by a mass of one kilogram under standard gravity (approximately 9.80665 m/s2). This means 1 kgf is equal to 9.80665 newtons (N).
The kilogram-force is not a coherent SI unit, and its use is generally discouraged in scientific and technical contexts. The SI unit of force is the newton. However, kilogram-force remains in use in some engineering fields and in everyday language where a rough estimate of force is acceptable.
It's important to distinguish between mass, measured in kilograms (kg), and force, measured in newtons (N) or kilogram-force (kgf). Mass is a measure of the amount of matter in an object, while force is an interaction that can cause a change in an object's motion. The kilogram-force expresses a force derived from a kilogram mass acted upon by gravity.
The term "kilopond" is largely obsolete but technically equivalent to kilogram-force.