A perfect graph is a type of graph in graph theory where every induced subgraph has a chromatic number equal to the size of the largest clique in that subgraph. This means that the graph can be colored using the minimum number of colors without any two adjacent vertices sharing the same color, and this number is determined by the cliques present in the graph. Perfect graphs include several well-known classes, such as bipartite graphs and circular arc graphs. The Strong Perfect Graph Theorem states that a graph is perfect if and only if it contains no odd cycles of length five or more as an induced subgraph.