FORWARD EDGES:- in a graph let there is a path like this...
A->B->C->D and there is edge form A->D then it called Forward Edge...
BACK EDGES:- and ig there is an edge from D to A then it is called back edge(means comming to node which is visited....)
CROSS EDGES:- let a path A->B->C->D and A->E->F and let there is edge like this F->C or F->D then it is cross edge..
TREE EDGES:- edges of grpah which is present in the DFS/BFS tree
