Convert

Create Network	Converts the selected LineString items tnto a network of Link items.
Geometry to Topology	Converts the selected Polygon items into link/node structure. The boundary of the original Polygon item is turned into Link items. A TopoPolygon seed is created inside the original Polygon which stores all the properties previously stored with the Polygon item.
Topology to Geometry	Converts the selected TopoPolygon items to simple Polygon items. The Polygon item will have all of the attributes which were stored on the TopoPolygon item. However the topological category property will be lost.
Copy Links as LineStrings	Copies Link Items as simple LineString Items. The original Link Items will remain and can be selected with the Select Item dialog: