posting vs flashcard

posting and flashcard both are nouns.

Word	Noun	Adjective	Verb	Adverb
posting	Yes	No	No	No
flashcard	Yes	No	No	No

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

posting: a sign posted in a public place as an advertisement
flashcard: a card with words or numbers or pictures that is flashed to a class by the teacher

Other hyponyms of posting include show bill, show card, theatrical poster, flash card.

posting (noun)	flashcard (noun)
the transmission of a letter	a card with words or numbers or pictures that is flashed to a class by the teacher
a sign posted in a public place as an advertisement
(bookkeeping) a listing on the company's records