A point object means an object having a certain mass with zero or negligible size . A point object is because it has only linear or translational motion. Probably a point object is only a hypothetical or imaginary concept , as in actual practice, we have bodies or objects which have definite size. These objects are known as an extended objects of definite size.
A real object is made up of large numbers of particles. These particles exert force on each other . The set of intereacting particles is known as a system of particles . Thus a system of particles is a set of large numbers of particles interacting with each other. For example , ant thing with mass , a ball , the earth , the sun, a molecule, a person etc. are the systems of particles.If a body moves on a horizontal surface in a every particle have the equal or same velocity is called translational motion.
However there is also rotational motion - Rotational motion is the motion of an object or a body rotating about a fix axis in a way that every particle has a circular motion with a fixed motion .for example - a wheel rotating over road in its axle or axis of rotation. The angular velocity of each particle of the body is same and equal to the angular velocity of the body.
Precession is the combination of rotational motion and the spin motion about a given axis of rotation . In other words precession is the spinning top of a rigid body. Axis of rotation is fixed.