TV show vs sitcom

TV show and sitcom both are nouns.

Word	Noun	Adjective	Verb	Adverb
TV show	Yes	No	No	No
sitcom	Yes	No	No	No

As nouns, sitcom is a hyponym of TV show; that is, sitcom is a word with a more specific, narrower meaning than TV show:

TV show: a program broadcast by television
sitcom: a humorous television program based on situations that could arise in everyday life

Other hyponyms of TV show include colorcast, colourcast, pilot, pilot film, pilot program, situation comedy, special.

TV show (noun)	sitcom (noun)
a program broadcast by television	a humorous television program based on situations that could arise in everyday life
	a humorous drama based on situations that might arise in day-to-day life