What is a Part
A part is a logical group of graphic elements characterized by attributes.
A drawing without parts is simply a collection of elements, i.e. lines, circles, dimensions, etc.
A parts drawing is a hierarchical set of logical groups created by the designer to meet his organizational needs.
The use of parts in a drawing responds to personal or corporate habits and uses; different users can create the same drawing with different and equally valid part structures.
n the geometry properties panel, in addition to the basic properties, the name of the part in which it is contained and any forced color for the light lines are shown.