Robot
In 1928, one of the first humanoid robots, Eric, was exhibited at the annual exhibition of the Model Engineers Society in London, where it delivered a speech. Invented by W. H. Richards, the robot's frame consisted of an aluminium body of armour with eleven electromagnets and one motor powered by a twelve-volt power source. The robot could move its hands and head and could be controlled through remote control or voice control. Both Eric and his "brother" George toured the world.
Cobot
Cobots resulted from a 1994 General Motors initiative led by Prasad Akella of the GM Robotics Center and a 1995 General Motors Foundation research grant intended to find a way to make robots or robot-like equipment safe enough to team with people. The first cobots assured human safety by having no internal source of motive power. Instead, motive power was provided by the human worker.
The cobot's function was to allow computer control of motion, by redirecting or steering a payload, in a cooperative way with the human worker. 
Later cobots provided limited amounts of motive power as well.