public speaking vs oral presentation

public speaking and oral presentation both are nouns.

Word	Noun	Adjective	Verb	Adverb
public speaking	Yes	No	No	No
oral presentation	Yes	No	No	No

As nouns, public speaking and oral presentation are synonyms defined as:

public speaking and oral presentation: delivering an address to a public audience

Other synonyms of public speaking include speaking, speechmaking.

public speaking (noun)	oral presentation (noun)
delivering an address to a public audience	delivering an address to a public audience