Define ‘Miner Extractable Value’ (MEV) and Provide a Common Example

MEV is the profit that miners (or validators in PoS) can extract by arbitrarily including, excluding, or reordering transactions within the blocks they produce. It is a measure of the total value they can gain beyond the standard block reward and transaction fees.

A common example is a 'DEX Arbitrage' bot that observes a price difference across two decentralized exchanges in the Mempool and submits a transaction to profit from it, paying a high fee to ensure front-running.