button ad vs advertizement

button ad and advertizement both are nouns.

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

As nouns, advertizement is a hypernym of button ad; that is, advertizement 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.
advertizement: a public promotion of some product or service

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

button ad (noun)	advertizement (noun)
small circular, rectangular, or square advertisement appearing usually at the bottom of a webpage.	a public promotion of some product or service