When discussing motion, it is important to be aware that there are several different types and that each type is dependent upon a particular frame of reference. Linear motion is the most basic form, involving the translation of a particle from one point to another in one dimension. Projectile motion, although two-dimensional, is easily analyzed by separating it into its linear components. Circular motion, is a special case of two-dimensional motion in which an object translates in a circular path.
Rotational motion is observed when an object itself turns about some internal axis.
The wheels of the car exhibit rotational motion about the axle. A pebble embedded in the tread of the car exhibits circular motion about the axle. A baseball spins towards a batter at home plate. From the perspective of a spectator, the ball is undergoing translational motion across the infield. However, the ball itself is rotating about its own axis.