In the lesson, we will describe what motion is, without considering the interaction of the moving particle with the outside world, or without considering the cause of the motion, using the particle model. We will provide a definition of motion variables according to their suitability in describing the motion of each moving body, especially if the moving body is moving in one dimension. The lesson is an introduction to the study of mechanics, with its two branches, kinematics and dynamics, for moving rigid bodies.