The simplest kind of Poker tournament takes place at just one table. Usually 8-10 players enter the event, through some sites have special two-seat tables for heads-up play.
As players ‘bust out’ (i.e. lose their last chip), nobody takes their place and the table gets shorter and shorter handed. Eventually, one player wins all the chips and the tournament is over. At that point, the prize pool is divided among the players according to some payout schedule. Typically, the first place player gets about half the money whilst the second and third get smaller shares, perhaps 30% and 20%.
The ‘multi-table’ tournament format allows a much larger number of people to play in the same event. As players throughout the tournament burst out, the Poker server moves players into the vacated seats and reduces the number of tables.
Eventually, play comes down to two opponents, just like in a single-table event, and ends when one player wins all the chips. At that point, the prize pool is divided among the top-finishing players.