Fluid dynamics is the branch of physics that deals with the study of fluids (liquids and gases) in motion. It involves understanding how fluid velocity, pressure, density, and temperature change within a flow system. Key concepts in fluid dynamics include flow patterns (laminar vs. turbulent), the conservation of mass and energy, and the forces acting on fluids, such as viscosity and pressure gradients. The study is governed by fundamental equations like the Navier-Stokes equations, which describe how fluids behave under different conditions. Fluid dynamics is crucial in various fields, from aerodynamics and hydrodynamics to engineering applications like pipe flow, weather prediction, and the design of aircraft.