advert vs button ad

advert and button ad both are nouns.

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

As nouns, button ad is a hyponym of advert; that is, button ad is a word with a more specific, narrower meaning than advert:

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

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

advert (verb)	button ad (verb)
make a more or less disguised reference to
make reference to
give heed (to)