If there is a directed path from any vertex to any other vertex then its strongly connected graph else it’s weakly connected.
In degree of a vertex v is the number of edges for which vertex v is a head and out degree is the number of edges for which vertex is a tail.
Graph is connected and there are no cycles in the graph.
Yes. By pushing all unvisited vertices adjacent to the one just visited and popping the stack to find the next vertex to visit.
First visit all the adjacent vertices of the start vertex and then visit all -the unvisited vertices adjacent to these and so on.