Composite nodes form tree nodes inside the Behavior Tree, and contain more than one thing to execute within them. There are three types of Composite nodes:
Selectors: Go through children from left to right looking for a successful node. If a node fails, it tries the next one. When successful, the node is completed and we can go back up the tree.
Sequence: Execute from left to right, until a node fails. If the node is successful, do the next one. If the node fails, go back up the tree.
Simple Parallel: Single task (purple) in parallel with some subtree (gray).