In the casinos and poker clubs, in what is referred to as a "ring game" (don't ask me why) the players provide their own money. Depending on the game that's being played, they bet at various intervals and the winner gets the entire pot, minus the "rake" -- typically a 5-10% commission that the "house" takes from each pot, which covers refreshments, a dealer, and the house profit.

In a tournament like you see on TV, the players pay an entry fee, and are provided with tournament chips which have no value outside of the tournament.

The game proceeds as above, execpt for the 5-10% commission, and the winners divide the total amount paid in as entry fees, minus, again, a commission for the house, based on a pre-specified prize structure, i.e. so much to the winner, so much for second place, third place, etc. depending on the number of entrants.