The central processing unit is a common component found in many devices. From laptops to phones and even automobiles, the CPU can be found. It is an essential part of the digital infrastructure.
But, the CPU was not always to be found. The first computers, which had no central processing units, were hard wired to their tasks and were unable to change without extensive rewiring. These systems are, now, referred to as fixed-program computers.
The CPU was born of the idea to run multiple tasks on a single system: Tasks will now be stored in the memory, which will be eventually sent to the Cpu for processing. These systems are called, stored-program computer.