What is a side pot in poker and how does it affect the outcome of a game?

In Poker, a side pot is created when one or more players go all-in and have different amounts of chips. The side pot is separate from the main pot and is contested only by the players who have contributed to it. This can affect the outcome of the game by allowing players with more chips to compete for a larger pot, while players with fewer chips can only win the main pot.