Join -EXPLODE
Join and Explode is a pair of topology operations for connecting and disconnecting selected parts of NURBS geometry.
Both tools work differently in specific selection modes.
NOTE:
If nothing is selected, then everything is selected (except object selection mode).
Point mode:
Only the geometry around the selected points is connected (join) or disconnected (explode).
Edge & Element mode:
The join operation is to connect of selected curves or segments of curves into curves.
The explode operation is to disconnect every selected curve segment as a separate curve.
Object mode:
The join operation unifies the geometry of all selected objects into one object.
The explode operation separates parts of an object as separate objects.
Objects can be exploded into separate connected parts(Objects), curves(Elements) and curve segments(Edges).