Introduction to Fluid StaticsEven though there are five states of matter, we generally come across three states of matter in our everyday life,i.e., solid, liquid and gaseous. Matter in stars is in the fourth state called plasma.
Fluid is a substance which can flow. Both liquids and gases are collectively referred to as fluids. Fluids play a major role in our lives. The air we breathe, the water we drink, etc., are examples of fluids.
Fluids can be either at rest or in motion. The properties of fluids at rest are discussed under fluid statics (hydrostatics) and the properties of fluids in motion are discussed under fluid dynamics or hydrodynamics.