Meaning of for, and usage of ','.

Affecting, with regard to, or in respect of
This is meaning one of meanings of 'for'
and following is example for this.

'The demand for money'
This somehow makes it awkward for me to apply the meaning.

When I only apply affecting, it sounds like the demand should necessarily have to make differnce to money.

And what makes me confuse more about it is that "with regars to", and "in respect of" doesn't seem to be necessary for sentence.
Also I can't figure out why there's comma in between.

Can someone make a sentence without comma but having same meaning as above?
and did I make misinterpretation of affecting?
what is difference between having comma after verbal known and not having?