prepositional object vs object of a preposition

prepositional object and object of a preposition both are nouns.

Word	Noun	Adjective	Verb	Adverb
prepositional object	Yes	No	No	No
object of a preposition	Yes	No	No	No

As nouns, prepositional object and object of a preposition are synonyms defined as:

prepositional object and object of a preposition: the object governed by a preposition

prepositional object (noun)	object of a preposition (noun)
the object governed by a preposition	the object governed by a preposition