Fluid statics (also called hydrostatics)'s the science of fluids at rest, and's a sub-field within fluid mechanics. The term usually refers to the mathematical treatment of the subject. It embraces the study of the conditions under which fluids are at rest in stable equilibrium. The use of fluid to do work's called hydraulics, and the science of fluids in motion's fluid dynamics. Pressure in fluids at rest Due to the inability to resist deformation, fluids exert pressure normal to any contactin… (More on Hydrostatics)