This document discusses robot end effectors. It defines an end effector as a device that attaches to a robot arm and enables it to perform specific tasks. There are two main types of end effectors: grippers, which grasp and manipulate objects, and tools, which perform processes like welding. It describes various types of grippers including mechanical, suction, magnetic, and adhesive grippers. Mechanical grippers use fingers actuated by different mechanisms like linkages, gears, cams, or screws to grasp objects. Gripper selection depends on factors like the object weight and geometry.