Have you heard the term "end effectors" before? It comes from robotic automation - it's defined as a device or tool that's connected to the end of a robot arm where the hand would be. It is also the part of the device that interacts with the environment. The type of end effector dictates how it can interact with that situation. For our purposes, the end effectors are the "hands" of the arm or crane and can take many forms depending on the task.