Simple Graph: unique connections, no reflexive connections
Multigraphs: multiple connections between two vertices permitted
Directed graphs/digraph
Pseudograph: permits self-links
Degree of vertex in an undirected graph: edges connected to vertex (loops contribute twice)
                 in a directed graph: in-degree is edges pointing to a vertex, out-degree is pointing out

Pendant vertex has degree 1
Sum of the degree of all vertices in an undirected graphs is twice the number of edges: handshake theorem
Bipartite: can be partitioned into two sets of vertices such that no edge connects two vertices in the same set
	Complete bipartite: two vertices are connected \iff they are in seperate partitions

	Matching in a bipartite graph: find a subgraph such that all vertices have *exactly* 1 edge attached