I think robots are anything that is powered by a motor or engine that is controlled by a person.  It can be all different sizes and shapes as long as it is made of some kind of metal and wiring it can be tiny or giant.  Some robots are super small that are used for picking small things up and the really big ones are used in factory's and other places that have big items they are making.  That is what I really think a robot is.

One real life occupation is car production.  They use robots on the assembly line making the cars and making sure they come off in one peace.  Before robots were used they had people on the assembly line making the cars which was a lot slower than the robots that is why they crated the robots for the car production industry.

Timeline
1495- Leonardo Di Vinci made a humanoid robot
1801- Automated loom was created
1822- Difference engine was created
1899- First remote controlled car
1946- The first general purpose digital computer
1947- Transistor was created
1948- Autonomous machines called Elmer and Elsie
1952- The first Numerically Controlled machine is built
1954- The first programmable robot arm
1961- The first industrial robot is installed in a General Motors automobile factory
1963- The first artificial robotic arm is controlled by a computer
1965- Homogeneous transformation first applied to robot kinematics
1970- The first mobile robot controlled by artificial intelligence.
1977- A European robot company, offers two sizes of electric powered industrial robots. Both robots use a microcomputer controller for programming and operation. 
1981- Takeo Kanade builds the direct drive arm. It is the first to have motors installed directly into the joints of the arm.
1989- A walking robot named Genghis is unveiled by the Mobile Robots Group at MIT.
1993- Dante an 8-legged walking robot developed at Carnegie Mellon University descends into Mt. Erebrus, Antarctica. Its mission is to collect data from a harsh environment similar to what we might find on another planet.
1994- Carnegie Mellon University (CMU) Robotics Institute's Dante II, a more robust version of its predecessor, descends into the crater of Alaskan (USA) volcano Mt. Spurr to sample volcanic gases.
1997- The first RoboCup football tournament is held in Nagoya, Japan.
1998- Scottish hotel owner Campbell Aird is fitted with the world's first bionic arm. 
1999-Sony builds Aibo. One of the first robots intended for the consumer market. It reacts to sounds and has some sort of preprogrammed behavior
2001- Built by MD Robotics of Canada, the Space Station Remote Manipulator System (SSRMS) is successfully launched into orbit and begins operations to complete assembly of International Space Station.
2002- Honda's ASIMO was the first robot that could walk independently with relatively smooth movements and could climb the stairs. 
2004- Epson releases the smallest flying robot. Weighing 0.35 ounces (10 grams) and measuring 2.8 inches (70 millimeters) in height, the Micro Flying Robot is unveiled as the world's lightest and smallest robot helicopter.