sorter vs collator

sorter and collator both are nouns.

Word	Noun	Adjective	Verb	Adverb
sorter	Yes	No	No	No
collator	Yes	No	No	No

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

sorter: a machine for sorting things (such as punched cards or letters) into classes
collator: a machine that selects, merges and matches decks of punch cards.

Other hyponyms of sorter include mailsorter.

sorter (noun)	collator (noun)
a machine for sorting things (such as punched cards or letters) into classes	a machine that selects, merges and matches decks of punch cards.
a clerk who sorts things (as letters at the post office)