Robots have replaced humans work

A robot is a mechanical device that can perform tasks automatically. It may – but need not – be humanoid in appearance. Some robots require some degree of guidance, which may be done using a remote control, or with a computer interface. A robot is usually an electro-mechanical machine that is guided by a program or circuitry. Robots can be autonomous, semi-autonomous or remotely controlled and range from humanoids such as ASIMO and TOPIO to Nano robots, 'swarm' robots, and industrial robots. By mimicking a lifelike appearance or automating movements, a robot may convey a sense of intelligence or thought of its own. The branch of technology that deals with robots is called robotics.
Machinery was initially used for repetitive functions, such as lifting water and grinding grain. With technological advances more complex machines were developed, such as those invented by Hero of Alexandria in the 1st century AD, and the automata of Al-Jazari in the 12th century AD. They were not widely adopted as human labour, particularly slave labour, was still inexpensive compared to the capital-intensive machines.
As mechanical techniques developed through the Industrial age, more practical applications were proposed by Nikola Tesla, who in 1898 designed a radio-controlled boat. Electronics evolved into the driving force of development with the advent of the first electronic autonomous robots created by William Grey Walter in Bristol, England in 1948. The first digital and programmable robot was invented by George Devol in 1954 and was named the Unimate. It was sold to General Motors in 1961 where it was used to lift pieces of hot metal from die casting machines at the Inland Fisher Guide Plant in the West Trenton section of Ewing Township, New Jersey.^[1]
Robots have replaced humans^{[citation needed]} in the asristance of performing those repetitive and dangerous tasks which humans prefer not to do, or are unable to do due to size limitations, or even those such as in outer space or at the bottom of the sea where humans could not survive the extreme environments.
Some people have developed an awareness of potential problems associated with autonomous robots and how they may affect society. Fear of robot behaviour, such as the Frankenstein complex, drive current practice in establishing what autonomy a robot should and should not have.

The word robot can refer to both physical robots and virtual software agents, but the latter are usually referred to as bots.^[2] There is no consensus on which machines qualify as robots but there is general agreement among experts, and the public, that robots tend to do some or all of the following: move around, operate a mechanical limb, sense and manipulate their environment, and exhibit intelligent behavior — especially behavior which mimics humans or other animals.
There is no one definition of robot which satisfies everyone and many people have their own.^[3] For example Joseph Engelberger, a pioneer in industrial robotics, once remarked: "I can't define a robot, but I know one when I see one."^[4] According to the Encyclopaedia Britannica a robot is "any automatically operated machine that replaces human effort, though it may not resemble human beings in appearance or perform functions in a humanlike manner." Merriam-Webster describes a robot as a "machine that looks like a human being and performs various complex acts (as walking or talking) of a human being", or a "device that automatically performs complicated often repetitive tasks", or a "mechanism guided by automatic controls