If the two graphs are isomorphic, then their distance is zero. And this distance increases, if vertices or edges are added or removed to/from one of the graphs.
Does this "distance" have a special name, or definition?
This distance function should return the minimal number of steps, to transform one graph to an another given graph, using edge/vertex adding/removing
The graph may be directed or not, but the edges aren't weighted (in my case)
Note: I don't ask you for an algorithm which calculates is. I'm just looking for the name (and the correct definition) of this thing, which I call "distance"