algorithms – Doubt on Graph on DFS

Maximum number of possible edges in a non-directed graph at 5 nodes, when the DFS call is made on any random node of the result stack size of the graph 5, that is, 5 calls from function present simultaneously in the stack are ____________________

How can the edges of a graph be converted into a function call? Does this mean that we have to make a recursive call? I am not clear, what is the function call here. Plz help