In short
A robotic arm is a programmable industrial manipulator that moves on joints similar to those of a human arm and picks, moves or processes parts with the tool at its end.
Industrial robotic arms usually have 4 to 7 axes. The gripper, vacuum cup or custom tool at the end (the end effector) is chosen to suit the task.
Robotic arms are used for repetitive work such as pick & place, palletising, machine tending, packaging and vision-guided quality control. Payload, reach, cycle time and repeatability drive the selection.
To work productively on the floor, a robotic arm needs a robot cell with conveyors, sensors, safety equipment and PLCs, connected to production systems.