Outs are the cards remain in the deck that may improve your hand, ideally to complete a hand strong enough to win the pot.

AA for example, is a favorite hand against Heart AK pre-flop, but it can become a big problem if the flop comes, Qheart, 8heart, 2spades.

However, if you leave another heart on the turn or river, make a flush, and unless another player has a full house or better, you win the hand. There are 13 cards in each suit in the deck. You have two of them and two others are on board. Four cups of 13 have already been given, which means that they are still nine hearts in the deck.
 
This means there are nine cards that can improve your hand (probably) for a winning hand. Have nine outs. Remember, there are 13 cards of each suit in the deck.

 

this is a  bad post ? :o