Fluid refers to a state of matter wherein the matter yields to sideways or shearing forces. Gases, plasmas and liquids are considered to be fluids. They can be found in stationary as well as moving forms. The physics of stationary fluids is studied under fluid statics, whereas fluid mechanics is a branch of physics involved in the study of mechanics related with fluids and the forces they generate. It has applications in many fields such as mechanical engineering, biomedical engineering, chemical engineering, civil engineering, oceanography, biology, geophysics, astrophysics and meteorology. Some of the prominent relationships which are studied under this discipline are kinematic, regulating, stress, constitutive, and conservation relationships. This book explores some important selected concepts related to fluid mechanics. The various studies that are constantly contributing towards advancing technologies and evolution of fluid mechanics are examined in detail. The book aims to serve as a resource guide for students and experts alike and contribute to the growth of the discipline.