typewriter vs serial printer

typewriter and serial printer both are nouns.

Word	Noun	Adjective	Verb	Adverb
typewriter	Yes	No	No	No
serial printer	Yes	No	No	No

As nouns, serial printer is a hypernym of typewriter; that is, serial printer is a word with a broader meaning than typewriter:

typewriter: hand-operated character printer for printing written messages one character at a time
serial printer: a printer that prints a single character at a time

Other hypernyms of typewriter include character-at-a-time printer, character printer.

typewriter (noun)	serial printer (noun)
hand-operated character printer for printing written messages one character at a time	a printer that prints a single character at a time