S vs s

S and s both are nouns.

Word	Noun	Adjective	Verb	Adverb
S	Yes	No	No	No
s	Yes	No	No	No

As nouns, S and s are synonyms defined as:

S (noun)	s (noun)
(thermodynamics) a thermodynamic quantity representing the amount of energy in a system that is no longer available for doing mechanical work	the 19th letter of the Roman alphabet
the 19th letter of the Roman alphabet	1/60 of a minute; the basic unit of time adopted under the Systeme International d'Unites
a unit of conductance equal to the reciprocal of an ohm
the cardinal compass point that is at 180 degrees
an abundant tasteless odorless multivalent nonmetallic element; best known in yellow crystals; occurs in many sulphide and sulphate minerals and even in native form (especially in volcanic regions)