Velocity is a term used in physics and engineering to describe the rate at which an object changes its position. It is a vector quantity that includes both speed and direction. In simple terms, velocity is the speed of an object in a particular direction. It is often used in the study of mechanics, kinematics, and fluid dynamics to analyze the motion of objects and systems. Velocity can be calculated using the formula v = Δx/Δt, where v is velocity, Δx is the change in position, and Δt is the change in time. Velocity is an important concept in understanding how objects move and interact in a variety of systems.