Some entities can be exploded, or decomposed, into a set of simpler elements. The specific behavior depends on the class. For example, boxes can be exploded into regions, then lines. Polylines can be exploded into line segments. An mtext entity can be exploded into a separate text entity for each line of the original object. An mline entity can be exploded into individual lines. When you explode a block reference, AutoCAD copies all entities in the block reference and then splits them into their components.
More details as follows:
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