floor cover vs rug

floor cover and rug both are nouns.

Word	Noun	Adjective	Verb	Adverb
floor cover	Yes	No	No	No
rug	Yes	No	No	No

As nouns, rug is a hyponym of floor cover; that is, rug is a word with a more specific, narrower meaning than floor cover:

floor cover: a covering for a floor
rug: floor covering consisting of a piece of thick heavy fabric (usually with nap or pile)

Other hyponyms of floor cover include mat, parqueterie, parquetry, carpet, carpeting.

floor cover (noun)	rug (noun)
a covering for a floor	floor covering consisting of a piece of thick heavy fabric (usually with nap or pile)