In the field of chemistry, pressure can be defined as the force that is applied per unit of area, according to KentChemistry.com. Pressure is taken into consideration when dealing with gases.
KentChemistry.com explains that pressure in gases is produced when the particles of the gases hit the walls of the container where they are stored. To measure the pressure of air, the force with which the particles hit the walls is divided by area of the surface. University of California, Davis notes that the pressure exerted by air is rarely noted. For example, the pressure exerted by moving air is only noted when the wind is very strong. This is not the case for liquids and solids.