man vs human being

man and human being both are nouns.

Word	Noun	Adjective	Verb	Adverb
man	Yes	No	Yes	No
human being	Yes	No	No	No

As nouns, human being is a hypernym of man; that is, human being is a word with a broader meaning than man:

man: all of the living human inhabitants of the earth
human being: any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage

Other hypernyms of man include group, grouping, homo, human, man.

As nouns, man and human being are synonyms defined as:

man and human being: any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage

Other synonyms of man include homo, human.

man (noun)	human being (noun)
all of the living human inhabitants of the earth	any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage
any living or extinct member of the family Hominidae characterized by superior intelligence, articulate speech, and erect carriage
game equipment consisting of an object used in playing certain board games
an adult person who is male (as opposed to a woman)
someone who serves in the armed forces; a member of a military force
the generic use of the word to refer to any human being
a manservant who acts as a personal attendant to his employer
an adult male person who has a manly character (virile and courageous competent)
a male person who plays a significant role (husband or lover or boyfriend) in the life of a particular woman
a male subordinate

man (verb)	human being (verb)
provide with workers
take charge of a certain job; occupy a certain work place