Cards of different suits. In hold'em usually refers to a player's hole cards.
A straight draw that can be completed with cards of two ranks. E.g. either a 7 or a 2 will make 6543 a straight. An outside straight flush also requires that the card be of the same suit as the other four cards.
A card higher that the cards on the board.
A pair higher in rank than the highest card on the board.
Fold one's hand.
A card that, if discarded, reduces the chance of making one type of winning hand. E.g. If a player is dealt KQJ105, all of the same suit, and discarded the 5, it makes a flush less likely.
A player uses all five community cards to make their hand, since their hole cards are useless.
The cards dealt face down to the player.