Definition of the word 'robot', what (who) is it?

Question

Robotics

Hello.
A few questions on the same topic (please give answers in your own words):
1) what is a robot?
2) why is a robot called 'intelligent machine (thinking and making decisions independently)', and sometimes 'machine acting according to a given program'?
3) if we take two robots. The first one has an intellect, the second one has a small program, why are they called with one word "robot"?

Answer 1

It's just that one science fiction writer called the car that did something there. "Worker" is translated from Czech, which actually corresponded to the activity of the robot in the work.