You create blocks by associating objects and giving them a name.
After you define a block in a drawing, you can insert a block reference in the drawing as many times as necessary. Use this method to create blocks quickly.
The objects in an inserted block can retain their original properties, can inherit properties from the layer on which they are inserted, or can inherit the properties set as current in the drawing.
Block references that contain other blocks are known as nested blocks. Using blocks within blocks can simplify the organization of a complex block definition.
A block library is a collection of block definitions stored in a single drawing file. You can use block libraries supplied by Autodesk or other vendors or create your own.
You can use tool palettes to organize blocks that are stored in one drawing file or separate drawing files.
You can convert objects to construction geometry in the Block Editor.