Subject: Understanding blocks

A block can consist of visible entities such as lines, arcs, and circles as well as visible or invisible data called attributes. You can use attributes to track things such as part numbers and prices and to export attribute information to an external database. You can also track the number of parts by counting the number of times a block has been inserted into the drawing. Blocks are stored as part of the drawing file.    

External references have similar uses to blocks. Using external references, you can attach entire drawings to your current drawing. Unlike a block, however, an external reference does not become part of the current drawing.    

You can save blocks to an external .dwg file from the Explorer. You can also use the Explorer to manage and insert copies of blocks. The Explorer window lists the names of all blocks contained in the current drawing, along with other information about each block or external reference.    

You can also rename a block, modify its insertion point, and change the path of an externally referenced drawing by single-clicking on the property and making your edits within the Explorer.

In addition to the Explorer, you can also work with blocks by using the Block Editor, by using various block commands, and by adding blocks to tool palettes. For more details about the Block Editor and various block commands, see Working with blocks. For more details about tool palettes, see Customizing tool palettes.