What is pressure?Pressure is the force applied perpendicular to the surface of an object per unit area over which that force is distributed.
InputPound Per Square Inch (more accurately: Pound-force Per Square Inch, lbf/in²) is a unit of pressure or of stress based on avoirdupois units. It is the pressure resulting from a force of one pound-force applied to an area of one square inch.
Standard Atmosphere is a unit of pressure defined as exactly 101,325 Pa (1.01325 bar). It is the current average atmospheric pressure on Earth at sea level that is sometimes used as a reference pressure or standard pressure.