Centrality measures are metrics used in network analysis to identify the most important nodes within a graph. These measures help determine a node's influence or prominence based on its position and connections to other nodes. Common centrality measures include degree centrality, closeness centrality, and betweenness centrality, each providing different insights into a node's role in the network. Degree centrality counts the number of direct connections a node has, while closeness centrality assesses how quickly a node can reach others in the network. Betweenness centrality evaluates how often a node acts as a bridge along the shortest paths between other nodes, highlighting its potential to control information flow.