advertizing vs ad

advertizing and ad both are nouns.

Word	Noun	Adjective	Verb	Adverb
advertizing	Yes	No	No	No
ad	Yes	No	No	No

As nouns, advertizing and ad are synonyms defined as:

Other synonyms of advertizing include advert, advertisement, advertising, advertizement.

advertizing (noun)	ad (noun)
a public promotion of some product or service	a public promotion of some product or service