A robot is a machine designed to execute repetitive tasks. Some robots are controlled by a human operator, but most robots are controlled by a computer processor. An autonomous robot that can act independently of direct operator control is the ideal or goal of robotics. Insect robots work in "fleets ranging in number from a few to thousands, with all fleet members under the supervision of a single controller. The term insect arises from the similarity of the system to a colony of insects, where the individuals are simple but the fleet as a whole can be sophisticated. (whatis.techtarget.com)"

Science-fiction author Isaac Asimov developed Three Laws of Robotics in a short story titled Runaround he wrote in the 1940s. Asimov's laws include:

1. Robots must never harm human beings or, through inaction, allow a human being to come to harm.
2. Robots must follow instructions from humans without violating rule 1.
3. Robots must protect themselves without violating the other rules.

The origin of the term robot is from a science fiction book and a play written by Karel Capek. The book is titled Valka s Mloky (War with the Newts) and the play is titled R.U.R (Rozuma Univerzalni Roboti) [rozum means wisdom] (Rozum's Universal Robots). The Czech word robota means drudgery or compulsory labors.

from http://whatis.techtarget.com
http://www.jeffbots.com/dictionary.html
http://www.free-definition.com/Robot.html
http://www.frc.ri.cmu.edu/robotics-faq/TOC.html