In 1945, the mathematician John von Neumann demonstrated that a computer that is fixed in structure could execute any and all kind of computation, as long as there is proper programming for the computer to execute. Prior to this hardware had to be changed in order to execute specific tasks. This was cumbersome and time consuming.
When he designed his computer model in the 1940’s von Neumann had two main components: a Central Processing Unit or the CPU and memory. The CPU during those times was broken down into two distinct units, the Control Unit and the Arithmetic Unit. Each component had its own purpose, the Control Unit reads and interpret the programming codes and converts them to electrical signals that activates other components of the computer. The Arithmetic Unit takes care of the mathematical and logical operations. The memory took care of storing data in its cells so that the processor can randomly access it when needed. This is the basis of how all digital computers works and it’s even true today. Below is a diagram of the von Neumann diagram from the 1940’s.
Memory (RAM) Control Unit
Arithmetic Unit

These two made up the CPU

Input Devices Keyboard -Mouse

Working Storage RAM As time went on there were minor changes to the von Neumann model but the biggest change was the combination of the Control Unit and the Arithmetic unit into a single unit, that we refer to now as the CPU or processor. Here is a diagram of the current von Neumann diagram that is still in used today.
Permanent Storage HD - CD/DVD Disk
Output Device Printer - Monitor
CPU

From the above diagram you can see we have a CPU which responsible for doing the calculations and tell the rest of the computer what to do. Secondly we have the Working Storage or RAM that stores data that the processor needs to run. This is temporary storage and when