Humanities › History & Culture The Definition of a Robot Science fiction has become science fact with robots and robotics Share Flipboard Email Print Monty Rakusen / Getty Images History & Culture Inventions Famous Inventions Famous Inventors Patents & Trademarks Invention Timelines Computers & The Internet American History African American History African History Ancient History and Culture Asian History European History Genealogy Latin American History Medieval & Renaissance History Military History The 20th Century Women's History View More By Mary Bellis Inventions Expert Mary Bellis covered inventions and inventors for ThoughtCo for 18 years. She is known for her independent films and documentaries, including one about Alexander Graham Bell. our editorial process Mary Bellis Updated October 14, 2019 A robot can be defined as a programmable, self-controlled device consisting of electronic, electrical, or mechanical units. More generally, it is a machine that functions in the place of a living agent. Robots are especially desirable for certain work functions because, unlike humans, they never get tired; they can endure physical conditions that are uncomfortable or even dangerous; they can operate in airless conditions; they do not get bored by repetition, and they cannot be distracted from the task at hand. The concept of robots is a very old one yet the actual word robot was invented in the 20th century from the Czechoslovakian word robota or robotnik meaning slave, servant, or forced labor. Robots don't have to look or act like humans but they do need to be flexible so they can perform different tasks. Early industrial robots handled radioactive material in atomic labs and were called master/slave manipulators. They were connected together with mechanical linkages and steel cables. Remote arm manipulators can now be moved by push buttons, switches or joysticks. Current robots have advanced sensory systems that process information and appear to function as if they have brains. Their "brain" is actually a form of computerized artificial intelligence (AI). AI allows a robot to perceive conditions and decide upon a course of action based on those conditions. Components of Robots Effectors — "arms," "legs," "hands," "feet"Sensors — parts that act like senses and can detect objects or things like heat and light and convert the object information into symbols that computers understandComputer — the brain that contains instructions called algorithms to control the robotEquipment — this includes tools and mechanical fixtures Characteristics that make robots different from regular machinery are that robots usually function by themselves, are sensitive to their environment, adapt to variations in the environment or to errors in prior performance, are task-oriented and often have the ability to try different methods to accomplish a task. Common industrial robots are generally heavy rigid devices limited to manufacturing. They operate in precisely structured environments and perform single highly repetitive tasks under pre-programmed control. There were an estimated 720,000 industrial robots in 1998. Tele-operated robots are used in semi-structured environments such as undersea and nuclear facilities. They perform non-repetitive tasks and have limited real-time control.