Dynamics is a science relating motion. It deals with the motion and velocity, acceleration, force and energy of large body, e.g., airplane, train, car and small object like atom, electron etc. It is concerned with the motion of material objects in relation to the physical factors that affect them: force, mass, momentum, energy. Dynamics establishes relation, investigates the nature of motion created due to the application of force on a body. In order to express the characteristics of motion of a moving body we need to know various terms relating motion.
Before starting to play football, cricket, tennis we should have general knowledge about how to start playing. Similarly at the beginning of learning dynamics a student should learn about velocity, acceleration, laws of falling bodies, gravitation and will be able to apply them in different graphs of motion.