superior vs upper

superior and upper both are nouns.

Word	Noun	Adjective	Verb	Adverb
superior	Yes	Yes	No	No
upper	Yes	Yes	No	No

superior (noun)	upper (noun)
a character or symbol set or printed or written above and immediately to one side of another character	piece of leather or synthetic material that forms the part of a shoe or boot above the sole that encases the foot
one of greater rank or station or quality	a central nervous system stimulant that increases energy and decreases appetite; used to treat narcolepsy and some forms of depression
the head of a religious community	the higher of two berths
a combatant who is able to defeat rivals

superior (adjective)	upper (adjective)
written or printed above and to one side of another character	the topmost one of two; upper
of or characteristic of high rank or importance	higher in place or position
of high or superior quality or performance	superior in rank or accomplishment
having an orbit farther from the sun than the Earth's orbit
(sometimes followed by `to') not subject to or influenced by
having a higher rank
(often followed by `to') above being affected or influenced by