flashcard vs greeting card

flashcard

noun
  • A card used to aid rote memorization. One side of the card contains data of one kind, or a question, and the other side contains the associated response which one wants to memorize. For example, one side could contain an English word, and the other side the Spanish translation. 

  • A solid-state digital memory storage format, commonly found on computers, digital cameras and cellphones. 

greeting card

noun
  • A card, typically folded in half and available commercially, that is sent to someone as a greeting. (This entry is a translation hub.) 

How often have the words flashcard and greeting card occurred in a corpus of books? (source: Google Ngram Viewer )