Overview
Liquidity mining is a specific incentive program where a DeFi protocol distributes its native tokens to users who provide liquidity to its pools. It is a way for new projects to 'bootstrap' liquidity and distribute their tokens to the community.
Difference from Yield Farming
While yield farming is the general practice of seeking returns, liquidity mining specifically refers to earning the protocol's own tokens as a reward for providing liquidity.
Goal
To ensure there is enough depth in the trading pools so that users can trade with minimal slippage.