A clade is a common ancestor and all the descendants of that common ancestor, including any new lineages. It is a single “branch” of an evolutionary tree. A phylogenetic tree represents many different clades, and defining a clade depends on the level of interest. A specific clade starts at a node and includes all the branches and nodes below it, and clades can be nested within clades. Similarly, a big branch of a tree can have many small branches. Either a big or a small branch can be considered a clade as long as the branch includes all of the descendants only.