Unroute converts copper traces back to unrouted signals, ready for re-routing. The following settings are presented in the Unroute dialog that appears after clicking any of the Unroute commands:
Object, converts a routed segment to an unrouted signal, deletes a via, and a polygon becomes an outline.
All, converts all segments into unrouted signals.
Incomplete, converts all stubs, segments without either a beginning or an end, to unrouted signals.
Connection, converts all copper connected to the selected segment to an unrouted signal, including those on other layers.
Connection Same Layer, converts the selected segment to an unrouted signal.
Signal, converts all segments with the same name as the selected segment to unrouted signals. This can include multiple branching traces.
Between components, converts the shared segments between two components into unrouted signals.
From to, converts the segments, shared between two connected terminals of any kind, into unrouted signals.