What is the difference between nothing and space

A theory i’ve thought about a while, something like this:

 

A question is, is space nothing or what is nothing. Absolutely nothing might not exist because if space and nothing is different we would not know what nothing is because everything void of something existing such as air, or anything that can be measured, scaled, detected. If something such as nothingness exists in physical form, where would it exist, would it cause a vacuum of the nearest things that exist around that particular nothingness?

 

Nothing might mean, something that does not exist but the existence of anything does not mean if that thing would not exist that it is nothing beforehand.

Existence and nothingness would then be in the same theory, existence is easy to explain however. It is easier to believe in existence in general compared to absolutely nothing or nothingness.

In physics the word nothing can hardly exist since this would be referred to as a vacuum which in itself would also have properties.

Nothing cannot exist if you really think about it.