The force, applied on a unit area of a surface is known as pressure Pressure=force/areaonwhichitactsPressure=force/areaonwhichitacts.
If the area is smaller, then the pressure on a surface would be greater; e.g. this is the reason that the area of one end of a nail is pointed toexertsufficientpressuretoexertsufficientpressure and other end is bigger asshownintheimagegivenbelowasshownintheimagegivenbelow.
This envelop of air is known as the atmosphere that extends up to many kilometers above the surface of the earth.
The pressure exerted by the air is known as atmospheric pressure.
The pressure inside our bodies is exactly equal to the atmospheric pressure and annuls the pressure acting from outside seetheimagegivenbelowseetheimagegivenbelow.
Liquids and gases also exert pressure on the walls of their respective containers.
