A computer is the brain of every robot, it is the logic engine and ultimately the controller. The computer is the second of the required three components that a robot must have, the other two being the mechanical components of the robot and the software. The software determines how the computer will operate or, more specifically, how the robot will respond to programming and its environment.
The robot is told what its has to do with a program that is written in a language that it understands. The computer is the part of the robot that provided the programming function, the decision-making function and the memory function as needed by every programmable machine.
Just as the brain is the essence of every human being and our education defines our capabilities so the computer defines what the computer will be able to do for the robot and the software defines how it will do it. Neither can make up for the shortcomings of the robot.