speaker vs tweeter

speaker and tweeter both are nouns.

Word	Noun	Adjective	Verb	Adverb
speaker	Yes	No	No	No
tweeter	Yes	No	No	No

As nouns, tweeter is a hyponym of speaker; that is, tweeter is a word with a more specific, narrower meaning than speaker:

speaker: electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance
tweeter: a loudspeaker that reproduces higher audio frequency sounds

speaker (noun)	tweeter (noun)
electro-acoustic transducer that converts electrical signals into sounds loud enough to be heard at a distance	a loudspeaker that reproduces higher audio frequency sounds
someone who expresses in language; someone who talks (especially someone who delivers a public speech or someone especially garrulous)