They are automatic machines that extend human potential. They cannot be programmed and does not contain a complex circuitry.
E.g.: The best example of a simple level Robot is a semi automatic washing machine.
2- Middle level Robots
They are those Robots which can be programmed but cannot be reprogrammed. They are multi purpose devices. They have sensor based circuitry and can do work which humans do.
E.g.: The best example of a middle level Robot is the fully automatic washing machine
3- Complex level Robots
They are those Robots which can be programmed and also reprogrammed. They are reprogrammable, multifunctional, manipulators. They contain a model based circuitry and are very complex.
E.g.: The best example of a complex level Robot is the personal computer.