In comparison with sidechains, Layer 2 rollups are thought of by many builders to be the safer manner for Ethereum to scale. Rollups, like sidechains, take the stress off of Ethereum by executing transactions on a separate blockchain. Transactions are “settled” on the rollup chain, bundled up, after which “posted” to Ethereum. In contrast to sidechains, rollups borrow their safety from the Ethereum mainnet – they use fancy cryptography and different strategies (like a multi-day dispute interval) to permit Ethereum mainnet nodes to substantiate that transactions are official.
