Neumann's architecture is one in which a single memory location (memory address)can be used either to store data or program and not both.for example if locations from 8000 to 8050 are used to store a program then input and output data cannot be in locations from 8000 to 8050.Normally microprocessors follow neumann architecture
Whereas in Havard architecture normally followed by microcontrollers,there will be separate data and program memory.Both can have same address,so that if program is from location 8000 to 8050 in program memory data can be stored in locations from 8000 to 8050 in data memory ie same address can be used for data nad program
(It seems you may be asking about "John von Neumann", not "von Newman".)
I'll take a shot...if I'm wrong...someone else can take two shot's...one at the answer and one at me!
John von Neumann was the Hungarian-American mathematician and polymath who invented EDSAC...the world's first stored-program computer to operate a regular computing service...using local memory.
With that said..."Von Neumann's computer Architecture" is the umbrella term for that type of functionality...stored-program computers operating a regular computing service using local memory.
Von Neumann architecture is a stored program architecture with no differentiation between data and instruction memory (both are residing on a single chip)
The concept of no differentiation between data and instruction memory is correct, but being on one chip has nothing to do with it. Most computer memories today require multiple chips. Back when von Neumann did his work integrated circuit chips hadn't even been invented, let alone used for storage - that didn't come until the 1970s.
Also, von Neumann didn't "invent" EDSAC. Some of his ideas inspired it, but its lead designer was Maurice Wilkes.
An important aspect of a von Neumann machine is that it implements a Turing-complete Finite State Machine - that is, the machine follows a program in a series of discrete steps, ending in a specific state after each step.
See the Wikipedia article on this subject for more specifics of a von Neumann machine (link at bottom of this article).
Von Neumann proposed the architecture for the computers we use today - the constant cycle around and access to memory on trip around the loop. As we press a key etc we interrupt the loop. The 8086 computers, etc., all used this technology. As technology has advanced to we have found ways to store instructions - pipelines, store memory, etc., for fast access in cache, but the basic principle of cycling round remains. This makes a misnomer of a PC being able to multitask. No PC can multitask; they all time-slice and take short intervals of time.
The modern PC is a little like an old motor car. You add things to it, you can give it bigger wheels, put shiny bits on it but at the end of the day its still an old motor car.
When Von Neumann gets put to bed so will all of the computer software we have running today.
Turing (earlier in the answer) and Babbage made adding machines.