cash advance vs sum of money

cash advance and sum of money both are nouns.

Word	Noun	Adjective	Verb	Adverb
cash advance	Yes	No	No	No
sum of money	Yes	No	No	No

As nouns, sum of money is a hypernym of cash advance; that is, sum of money is a word with a broader meaning than cash advance:

Other hypernyms of cash advance include amount, amount of money, sum.

cash advance (noun)	sum of money (noun)
an amount paid before it is earned	a quantity of money