Velocity is a fundamental concept in physics that quantifies the rate of change of an object's displacement over time. Because it specifies both how fast an object is moving and the direction in which it is traveling, velocity is classified as a vector quantity, unlike speed, which is a scalar quantity describing only magnitude. Mathematically, it is calculated by dividing the change in position (displacement) by the time taken to cover that distance. Changes in velocity are described by acceleration, which represents the rate at which the velocity vector changes. Understanding velocity is essential for analyzing motion across various physical systems, from mechanics to electromagnetism.