Use Blocks and Attributes
AutoCAD provides several features to help you manage objects in your drawings. With blocks you can organize and manipulate many objects as one component. Attributes associate items of information with the blocks in your drawings—for example, part numbers and prices.
Using AutoCAD external references, or xrefs, you can attach or overlay entire drawings to your current drawing. When you open your current drawing, any changes made in the referenced drawing appear in the current drawing.