A robot can be anything that has some sort of mechanical motion on it's own. We may not notice them every day but in certain places, robots can be all around us.

If you've ever been in a factory, there's a high chance you saw a robot in action, however it's not hard to miss one of those robots because they're the typical arm that is attatching objects to whatever they are designed to build.

Robots have been around since several hundred years B.C.
The first known automated object was a steam powered pigeon made by the greed philosopher Archytas. The bird was able to fly a few hundred yards before running out of steam.
The greeks being as primitive as they were compared to today's world, this is quite impressive.

Since then, technology and robotics have taken giant leaps toward being a huge part of our lives.