Are you just asking what the meaning of the abbreviation Pa is?
Pa is the abbreviation for the unit of measure known as the Pascal. This unit of measure is named after the French mathematician and physicist who experimented with barometers. A pascal is a unit of stress or pressure.
One pascal is equal to the one Newton of force applied over one square meter of area. Before 1971, the unit was simply known as a newton per square meter.
Without getting more information in your question, I can't give a better answer because I don't really know what you're asking.
The pressure acting on a surface is 10Pa means a force of one 10 Newton exerts on every square meter of area . Also if the a force of F is exerted on an area A , then the pressure P on the area is given by:
P = F/A Pascals,
Thus Pascal is the measure of the unit of pressure and its dimension is N/m^2 or as per dimensional analysis pascal has the indices if mass, length and time expressed like: MLT^-2/L^2 or [ M^1] [L^-1][T^-2].
Nomally pressure per unit area or the unit of pascals are used of mentioning air pressure, liquid pressure , tensile stress , shearing sress etc.