button ad vs advertising

button ad and advertising both are nouns.

Word	Noun	Adjective	Verb	Adverb
button ad	Yes	No	No	No
advertising	Yes	No	No	No

As nouns, advertising is a hypernym of button ad; that is, advertising is a word with a broader meaning than button ad:

button ad: small circular, rectangular, or square advertisement appearing usually at the bottom of a webpage.
advertising: a public promotion of some product or service

Other hypernyms of button ad include ad, advert, advertisement, advertizement, advertizing.

button ad (noun)	advertising (noun)
small circular, rectangular, or square advertisement appearing usually at the bottom of a webpage.	the business of drawing public attention to goods and services
	a public promotion of some product or service