Robot is a machanical, artificial agent and. It is usually an electromechanical system which automatically operates without human controlling. A robot gathers information about its environment (senses) and uses that information (thinks, search) to follow instructions to do work (acts).
There is endless variety in the size, shape and jobs of robots. Some robots are used day after day in factories, while others are highly experimental and use artificial intelligence to behave more and more like living creatures, able to act independently in changing environments. Robots are being designed to perform precision surgery, explore space, the ocean, other dangerous areas.

A robot is made up of 3 basic type of components:

1. Sensors
2. Actuators
3. Environments

Sensors

Sensor is a device used to detect real world objects and convert to electric signal which is similar to human senses. For example image sensor which is used to detect object and convert optical image to electric signal such as digital camera. There are many types of sensor.

Actuators

Actuator is a device to make robot movable. For example, robot's legs and arms.