public knowledge vs general knowledge

public knowledge and general knowledge both are nouns.

Word	Noun	Adjective	Verb	Adverb
public knowledge	Yes	No	No	No
general knowledge	Yes	No	No	No

As nouns, public knowledge and general knowledge are synonyms defined as:

public knowledge and general knowledge: knowledge that is available to anyone

public knowledge (noun)	general knowledge (noun)
knowledge that is available to anyone	knowledge that is available to anyone