The Solidity Events Guide I Wish I Had

The Ethereum blockchain relies on deterministic state updates to achieve consensus among nodes, allowing them to process transactions and arrive at the same latest state of the blockchain. However, the indeterministic nature of making a call from the Ethereum Virtual Machine (EVM) to the outside world poses challenges in achieving communication between Web2 and Ethereum. To address this issue, the EVM allows for the generation of logs, which include event signatures, topics, and data, and serve as a means of communication between the EVM and the outside world.