If ‘w’ is the specific weight of liquid and ‘k’ the depth of any point from the surface, then pressure intensity at that point will be

Fluid mechanics is the branch of physics concerned with the mechanics of fluids and the forces on them. It has applications in a wide range of disciplines, including mechanical, aerospace, civil, chemical and biomedical engineering, geophysics, oceanography, meteorology, astrophysics, and biology. (Source: Wikipedia)

Example of fluid mehanics in action:  Waste flowing through the sewer system, gases moving through an engine, or sap moving sucrose from the leaves to the distal parts of a tree, or even cars moving through the traffic grid.