A graph

A sub graph

Weighted graph(network)

The degree or valency(or order) of a vertex

A path

A walk

A cycle(circuit)

Two vertices are connected if

A graph is connected if

A loop

A simple graph

Digraph

A tree

A spanning tree of a graph,G,

A bipartite graph

A complete graph

A complete bipartile graph( denoted Kr, s)

Isomorphic graphs

An adjacency matrix

A distance matrix