A cash game, otherwise known as a "ring game" is a form of poker with no fixed start or end time. Cash games are rather permanent tables where players can come as go as they please. These games have a buy-in minimum (and maximum at no limits): the player must bring at least this much money to the table.
A tournament is a structured competition with a fixed starting point and completion when only one person remains. The tournaments have an entrance fee. Once paid that entitles the person to take part in the tournament. As soon as their chips are depleted they are out of the tournament
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