A card being discarded does not necessarily go to the Graveyard. Although this is normally the case, cards like "Macro Cosmos" will send the cards to the Banished Zone instead; however, the card is still considered as being discarded.
Also, just because a card is moved from the hand to the Graveyard does not mean that it is discarded. The wording of the card that causes a discarding action must specifically say "discard" to be considered as such. Cards that are specifically "sent" to the grave from the hand are not discarded. However, any card that is discarded is also considered "sent".