Gravity (g) which is defined by an acceleration of 9.80665m/s² is the designated average accelerating force due to Earth’s gravity at sea level.
The real actual acceleration due to gravity varies slightly depending on geo location and height relative to sea level.
Since the Earth’s gravitational force is used in many different physical calculations a fundamental constant value of 9.80665m/s² has been standardised as the average acceleration due to gravity at sea level.
Gravity is a major influence on many aspects of pressure measurement which include hydrostatic pressure, dead weight testers, g effect, specific gravity and barometric pressure.