When you win at blackjack, your payout is 3:2 (in most variants) instead of the standard 1:1. In simple terms, 3:2 means that for every 2 chips you bet, you get 3 chips. In other words, Since blackjack is 3/2 = 1.5, you can say that your bet is worth 1.5X. Example: If you betR$2 and hit blackjack at 3:2.
If you see "Blackjack pays 2 to 1", that's good news for you. This doesn't happen often anymore because most casino owners have figured out that 2 to 1 actually gives the player better odds than the house. But in case you do stumble upon a casino like this, make the most of it.