What is a robot?

Answer 1

A robot is a virtual or mechanical artificial agent. In practice, it is usually an electromechanical machine which is guided by computer or electronic programming, and is thus able to do tasks on its own. Another common characteristic is that by its appearance or movements, a robot often conveys a sense that it has intent or agency of its own.

The word "robot" comes from a Slavic term meaning "work" or "labor" and is related to the work of serfs in feudal times. So the major application of the term is to machines that do work, or metaphorically to people who work in the manner of an automaton, without personal concern or judgment.
One definition of robot is "artificial agent" (a better definition is in the link below). Artificial just means someone made it, agent means it does something for someone (my favorite robot is the dishwasher - someone built it to wash dishes for me). Many people assume "agency" includes the ability to act by itself (autonomy), or at least look like it can. These days most of the really popular robots are exploring places people can't go yet (Voyager left the solar system not too long ago, Spirit and Opportunity are still running around Mars) and doing things too dangerous for humans to do safely (like hunting for roadside bombs in war zones or searching the bottom of the ocean). I used to work with a parts placer in an electronics assembly plant, it took very small parts from reels and bins and placed them on circuit boards. Some car manufacturers use big industrial robots for welding and lifting cars and trucks. Nanotechnology is finally catching on, with motors and wheels the size of atoms. I have seen pictures of remote control robots for doing surgery from somewhere outside the hospital, like from Another Country. Anything you can build to do something for you is basically a robot.