Liquidity pools are a place to pool tokens (which can be called liquidity) so that users can use them to make trades in a decentralized way. These pools are created by users and decentralized apps (or Dapps, for short) who want to profit from its usage. To pool liquidity, the amount a user supplies must be equally divided between two coins: the primary token (sometimes called the quote token) and the base token (usually ETH or a stable coin). SushiSwap's liquidity pools allow anyone to provide liquidity here. When they do so, they will receive SLP tokens (SushiSwap Liquidity Provider tokens). If a user deposits $SUSHI and $ETH into a pool, they would receive SUSHI-ETH SLP tokens. These tokens represent a proportional share of the pooled assets, allowing a user to reclaim their funds at any point. Every time another user uses the pool to trade between $SUSHI and $ETH, a 0.3% fee is taken on the trade. 0.25% of that trade goes back to the LP pool.