TVL, or Total Value Locked, is a metric used to measure the total value of assets locked in a particular blockchain, DeFi protocol, or smart contract. It's a way to gauge the overall health and adoption of a specific ecosystem within the cryptocurrency space. In simpler terms, TVL represents the total amount of money that is currently being utilized within a particular platform or network.

To understand the concept better, let's consider an example. Imagine a decentralized lending platform that allows users to lend and borrow cryptocurrencies. The TVL of this platform would be the total value of all the assets that are currently being lent or borrowed. This metric gives us an idea of how much value is being generated within the platform and how widely it's being adopted.