John Von Neumann was famous mathematic scientist of his time and he had done analytcs of all of research till that from subject of numeric machines that are made before todays (his time) computers. He suggested simple concept how should universal Digital Machine should work. He wasn't interested in technical issues and their realization but he sugested global model.

Basic settings of Neumanns model are:
1) There must be import unit that is interface through computer will get import data that needs to be procesed. And also algorithm by which process will be done. Thre must also be output unit by which computer will present results of done process.

2) There must be unit that can execute arithmetic and logic operations and can make decisions (todays CPU)

3) datas and instructions are memored in same form so in specific surcomstances instructions can be treated as datas and vice versa. This is fundamental setting aldo it doesn't seem at first thaught and it was one of main setting that affected later development of computers.



Besides that Von Neumann suggested using a binary number system, but that isn't considered as fundamental setting because computer could workd with other number base. Mathematically can be shown that optimal value of base would be e=2,714 (base of natural logarithm). Technicaly isn't accepting that base is not rounded number. Closest round number is 3 so computer would work faster and more efficient with base 3. But, there isn't any cheap unit that has 3 stable conditions, thats why 2 is accepted as best solution. Von Neumanns model is also called sequencial because program is executed as sequence (array of instructions) by exact order, which is always interpreted as "tight neck" so that connection is called Neumanns defile.