Game formats also have a number of different types.
FREEZEOUT.
A game where a player pays a single entry amount & registration fee and receives one amount of chips. If a player loses all their chips they are out of the tournament and cannot buy back into the game.
REBUY.
This option allows each player to buy another stack of chips minus the registration fee, remain in their seat and continue the game. This can be if they either lose all their chips or go below a pre-determined amount of chips set before the game starts. Rebuys can be limited to set number per player or within a certain amount of time from the beginning of the game known as the REBUY PERIOD or to end of the LATE REGISTRATION period, where players don't have to be there at the start of the game but can still buy-in up to this point.
RE-ENTRY.
A player in this format can lose all their chips and buy back into the game but must pay the full amount inc the registration fee and will be seated at a different table and seat to where they lost their original stack. Normally used in larger tournaments.
There is often a lot of misunderstanding about the the above two formats so make sure you know the difference and factor this in when deciding how much you may need to play these tournaments.
Another option to consider is the ADD-ON. This is where you can purchase additional chips, normally at the break but can be earlier, to add to your existing chip stack so that you can afford the increasing blinds and it also adds to the total prizepool. Nearly all players will use this option whether or not they have already had a re-buy or re-entry.
There may be options for a Double Rebuy or Double Add-On but these will all be displayed on the screens at the casino or website info.