A cladogram is a diagram that illustrates the evolutionary relationships among various species or groups based on shared characteristics. It represents a branching tree structure, where each branch point (node) signifies a common ancestor and the lines represent the divergence of species from that ancestor. Cladograms are used in the field of phylogenetics to visualize and analyze the evolutionary history of organisms, highlighting their similarities and differences. Unlike phylogenetic trees, cladograms do not convey information about the time scale of evolution or the degree of divergence.