Intro to graaph theory

a graph G =(V,E) consists of a set of objects V ={v1,v2,…} called vertices and another set E ={e1,e2,…} , whose elements are called edges , such that each edge ek is identified with an unordered pair (vi,vj) of vertices

The verices vi,vj

An edge having the same vertex as both its end vertices is called a self-loop

more than one edge associated with a given pair of vertices are referred to as parallel edges

A graph without any self-loop or parallel edged is called simple graph

if the number of veritces is finite its called a finite graph, otherwise its a infinite graph