Cladistics is a method of classifying organisms based on their evolutionary relationships. It groups species into clades, which are branches on the tree of life that share a common ancestor. This approach emphasizes the importance of shared characteristics, known as synapomorphies, to determine how closely related different species are. In cladistics, organisms are represented in a diagram called a cladogram. Each branch point, or node, indicates a divergence from a common ancestor. This method helps scientists understand the evolutionary history of life on Earth and is widely used in fields like biology and paleontology.