I've never played craps, but have observed it several times in the past.
To start in a game of craps you place a bet on the pass or no pass line.
If you win on that line you get a 1:1 payout.
The pass and no pass lines are a couple of the easiest lines to win on, but you don't win a whole lot in return.
Once the point has been established in a game of craps, you can play the numbers to get an increased amount of odds winnings.
Craps can be a complex game of play and chance, and you can win a lot of money if there's a good shooter at the table.