ink-jet printer vs dot printer

ink-jet printer and dot printer both are nouns.

Word	Noun	Adjective	Verb	Adverb
ink-jet printer	Yes	No	No	No
dot printer	Yes	No	No	No

As nouns, dot printer is a hypernym of ink-jet printer; that is, dot printer is a word with a broader meaning than ink-jet printer:

ink-jet printer: a printer that produces characters by projecting electrically charged droplets of ink
dot printer: a printer that represents each character as a pattern of dots from a dot matrix

Other hypernyms of ink-jet printer include dot matrix printer, matrix printer.

ink-jet printer (noun)	dot printer (noun)
a printer that produces characters by projecting electrically charged droplets of ink	a printer that represents each character as a pattern of dots from a dot matrix