Any substance that flows is called a fluid. In other words fluids cannot undergo shearing or tensile stress. This chapter is dedicated to studying about the behavior (mechanism) of fluids. Fluid mechanism is a vital science and is used in hydraulic engineering, aviation etc. There are two major branches in fluid mechanics, namely, fluid statics which is the study of fluid in a stationary state and fluid dynamics which is the study of fluid when its flowing, like what happens when water flows? So lets dive into fluid mechanics.Fluids are readily able to flow because their intermolecular forces are comparatively week at room temperatures. Fluids do not have any specific shape and take the shape of the container into which they are filled. Fluids like air has no definite shape and are extremely turbulent.