afterward vs later on

afterward and later on both are adverbs.

Word	Noun	Adjective	Verb	Adverb
afterward	No	No	No	Yes
later on	No	No	No	Yes

As adverbs, afterward and later on are synonyms defined as:

afterward and later on: happening at a time subsequent to a reference time

Other synonyms of afterward include after, afterwards, later, subsequently.

afterward (adverb)	later on (adverb)
happening at a time subsequent to a reference time	happening at a time subsequent to a reference time