The Explode button breaks connections between entities inside of a complex object (block).
The Explode 
button can be found in the Editor tab under the Instruments section.
Select an object (block) and press the Explode button.
All entities inside the block having properties (color, linetype etc.) equal to By Block may change them when using Explode tool.
Example:
| • | Create a new drawing: select File -> New. |
| • | Add a simple set of entities: |
set the Color and the LineWeight properties for spline equal to By Block
| • | select the entities to be added as a block using Ctrl + A keys or using the mouse (click over entities with the Shift key pressed); |
| • | press the Copy  button (Edit -> Copy) to copy the selected entities to the Clipboard; |
| • | press the Paste as Block  button (Edit -> Paste as Block) to paste the copied entities as block; |
| • | set the block properties as Color - Purple, Line Weight - 1,58: |
as a result the color and the lineweight of the spline have changed according to the set block properties
| • | select the new block and press the Explode button (Editor Tab -> Instruments -> Explode): |
the spline gets its original properties and the entities can be moved separately which was impossible when they were united into a block.