A block is one or more objects combined to create a single object. Blocks help you reuse objects in the same drawing or in other drawings.
A block can be composed of objects drawn on several layers with various properties. You can use several methods to create blocks.
You create blocks by associating objects and giving them a name. You can also attach information (attributes) to a block.
Instead of being a fixed part of a drawing, a dynamic block reference can be changed or manipulated as you work in a drawing.
When you insert a block, you create a block reference and specify its location, scale, and rotation.
A dynamic block has flexibility and intelligence. A dynamic block reference can easily be changed in a drawing while you work. You can manipulate the geometry through custom grips or custom properties. This allows you to adjust the block reference in-place as necessary rather than searching for another block to insert or redefining the existing one.
You can attach information to blocks and later extract the information to create a bill of materials or other report.
You can modify a block definition or a block reference already inserted in the drawing.