an example of graph is given herelet' now go through some definitions of graphnode or vertexa pointusually represented by dot in graph the vertices or nodes are abcdand edgethis is connection between two vertices the line connecting and is an example of an edge loopwhen an edge from node is incident on itselfthat edge forms loop degree of vertexthis is the number of vertices that are incident on given vertex the degree of vertex is adjacencythis refers to the connection(sbetween node and its neighbor the node is adjacent to node because there is an edge between them patha sequence of vertices where each adjacent pair is connected by an edge directed and undirected graphs graphs can be classified based on whether they are undirected or directed an undirected graph simply represents edges as lines between the nodes there is no additional information about the relationship between the nodes than the fact that they are connected