How Does a ‘Revert’ Transaction on a DEX Differ from a Simple Cancellation on a CEX?

A revert transaction on a DEX (Decentralized Exchange) occurs when the execution fails due to a pre-set condition, like exceeding the slippage tolerance. While the state change (the trade) is reversed, the transaction is still broadcast and mined, meaning the user still pays the 'gas fee' for the computational work.

A simple cancellation on a CEX (Centralized Exchange) is an off-chain instruction that usually incurs no fee if the order was not executed.