The poker tournament has different stages in it to play. Cash games are relatively static. The blinds doesn't change. The stack sizes vary. You can leave the game from the table. Each chip in your hand has the value. In tournaments - blind size, ante, stack size and chip values are all can be varied. Mastering in these things is a very important skill. Starting the game with holdem in the early phase of a tournament is treated as a cash game, bubble and prize phases are treated as sit-n-gos. My primary focus is on the multi-table poker tournaments. The middle stage is treated as satellite play. In live tournaments it is very common to have stacks around 10BB level.