Robot

A robot is a machine that can carry out tasks on its own, or with very little help from a person. Robots are built from motors, sensors, and a computer brain. The computer brain runs a set of instructions called a program. The program tells the robot how to move, what to look for, and what to do next.

Robots come in many shapes. Some look like people, with arms, legs, and a head. Others look nothing like living things. A factory robot might be just a long metal arm that bolts car doors together all day. A vacuum robot is a flat disk that rolls around the floor. A Mars rover is a six-wheeled machine the size of a small car. The shape of a robot depends on the job it has to do.

Most robots work in three steps. First, they sense the world using cameras, microphones, or touch sensors. Next, the computer thinks about what the sensors picked up. Finally, the robot acts by moving a wheel, an arm, or a tool. This loop repeats many times each second.

Robots are useful for jobs that are dull, dirty, or dangerous. Factory robots build cars and pack boxes without getting tired. Surgical robots help doctors make tiny, careful cuts. Bomb-disposal robots roll up to a bomb so a human does not have to. Underwater robots dive to the bottom of the ocean, where the pressure would crush a person. Space robots like the Curiosity and Perseverance rovers explore Mars, which is more than 100 million miles from Earth.

The word "robot" is not very old. It comes from a 1920 play by a Czech writer named Karel Čapek. In the play, the robots are workers built to do hard labor. The idea caught on, and soon "robot" became the word for any machine that acts on its own.

Today, scientists are still arguing about what really counts as a robot. Is a self-driving car a robot? What about a smart speaker that talks back to you? Some experts say a real robot must move in the physical world. Others say software that thinks and acts on its own counts too. As machines get smarter, the line keeps getting blurrier.

One thing is clear. Robots cannot yet do many things humans do easily, like folding laundry or having a real conversation. The next time a robot vacuum bumps into a chair leg, remember: even the best robots are still learning how to live in our world.