Liquidity & Liquidity Pools
Liquidity is how easily an asset can be bought or sold without moving its price; a liquidity pool is a smart contract holding paired tokens that traders swap against.
In depth
On order-book exchanges liquidity comes from resting orders; on DEXs it comes from pools funded by users who earn a cut of trading fees. Deep liquidity means tight spreads and small slippage. Thin liquidity means a modest order can swing the price dramatically.
Why it matters
Liquidity determines the real price you get — not the number on the ticker.