fixed-width font vs typeface

fixed-width font and typeface both are nouns.

Word	Noun	Adjective	Verb	Adverb
fixed-width font	Yes	No	No	No
typeface	Yes	No	No	No

As nouns, typeface is a hypernym of fixed-width font; that is, typeface is a word with a broader meaning than fixed-width font:

fixed-width font: a typeface is which each character is given the same width (as by a typewriter)
typeface: a specific size and style of type within a type family

Other hypernyms of fixed-width font include case, face, font, fount.

fixed-width font (noun)	typeface (noun)
a typeface is which each character is given the same width (as by a typewriter)	a specific size and style of type within a type family