“Banker” has two meanings in casino language. In a general sense, it describes whoever holds the bank — the dealer or the house that pays winning bets. In baccarat, though, Banker is simply the name of one of the two hands on the layout, and that is where newcomers often get confused.
In most modern baccarat games, including Punto Banco, neither the Player hand nor the Banker hand belongs to anyone at the table. Both are dealt under fixed drawing rules, and players just bet on which will win, or on a tie. Backing Banker does not mean betting on the casino.
Because the drawing rules give the Banker hand a small statistical edge, casinos usually take a commission on winning Banker bets, traditionally 5%. No-commission tables instead reduce the payout on certain winning totals, so the exact rules should always be visible at the table.