Pressure is defined as the force acting perpendicular per unit area.
We can say force F is acting perpendicular to an area A, when pressure is applied.
Thus pressure experienced by the area A will be P = F/A
SI unit of pressure is Pascal (Pa). It is the pressure exerted perpendicularly by a force of 1N on an area 1 m2.
1 Pa = 1 N/1m2.
Regards.