Graph concepts G h d b ti ( d ) d d (li k )Graphs are made up by vertices (nodes) and edges (links). Summary: Graph concepts G h d b ti ( d ) d d (li k )Graphs are made up by vertices (nodes) and edges (links). An edge connects two vertices, or a vertex with itself ­ loop. AC, AC - multiple edges BB ­ loop The shape of the graph does not matter, only the way the nodes are connected to each otherconnected to each other. Simple graph - does not have loops (self-edges) and does not haveSimple graph does not have loops (self edges) and does not have multiple identical edges. Further reading:g http://www.utm.edu/departments/math/graph/glossary.html Symmetrical and directed graphs Two distinct types of edges: symmetrical and directed (also called arcs). Two different graph frameworks: graph, digraph = directed graph. In the digraph framework a symmetrical edge means the superpositionIn the digraph framework a symmetrical edge means the superposition of two opposite directed edges. Node degrees Node degree: the number of edges connected to the node 4ki =node. Collections: Biology and Medicine