Graph Theory Terminology: Vertices, Edges, Endpoints

[Gear2d]

I was wondering if I could get some help with the terminology when it comes to graph theory. In this picture : http://en.wikipedia.org/wiki/Image:6n-graf.svg the numerical values are vertices (or nodes as some call it), so what are the edges then (are they the lines that connect the nodes)? What would be considered a end vertices (endpoints), outgoing edges, and incoming edges?

 

[HallsofIvy]

Yes, the lines connecting the numbers are the edges. The "end vertices" or "endpoints" of an edge are the two numbers (nodes) at each end of an edge. Since this is not a directed graph (we are not given a direction to each edge- that is "from" one node "to" the other) there are no "incoming" or "outgoing" edges.