coverlet vs bed cover

coverlet and bed cover both are nouns.

Word	Noun	Adjective	Verb	Adverb
coverlet	Yes	No	No	No
bed cover	Yes	No	No	No

As nouns, bed cover is a hypernym of coverlet; that is, bed cover is a word with a broader meaning than coverlet:

Other hypernyms of coverlet include bed covering, bedcover, bedspread, counterpane, spread.

coverlet (noun)	bed cover (noun)
a decorative bedspread (usually quilted)	decorative cover for a bed