Fluid mechanics is a branch of mechanics that studies fluids and the forces on them. Fluid mechanics examines fluids in two subsystems: static and dynamic. Fluids, and especially air and water, have a major role in the life of creatures and 65% of our body is composed of water. It can be divided into fluid statics, the study of fluids at rest; and fluid dynamics, the study of the effect of forces on fluid motion
Hydraulics is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on the applied engineering using the properties of fluids. In its fluid power applications, hydraulics is used for the generation, control, and transmission of power by the use of pressurized liquids