# Modular Blockchain > A blockchain design that splits responsibilities across separate, specialised layers. Canonical URL: https://fudfomo.co/glossary/modular-blockchain Source: What The Block! Dictionary v1.0 (last updated 2026-04-25), browsable at https://wtb.fudfomo.co. ## Definition A modular blockchain breaks the work of running a chain into separate pieces: execution, settlement, consensus, and data availability. Each piece can be handled by a different network, optimised for its job. The opposite is a monolithic blockchain, like Bitcoin, that does all of these things itself. The modular approach is meant to give better scalability, with the trade-off that more moving parts can introduce more dependencies. ## Related terms - [Rollup](https://fudfomo.co/glossary/rollup): A type of layer 2 that bundles many transactions together and writes a summary back to the main chain. - [Layer 2](https://fudfomo.co/glossary/layer-2): A faster, cheaper network built on top of a layer 1 like Ethereum. Borrows the main chain's security. - [Data Availability](https://fudfomo.co/glossary/data-availability): The guarantee that the data behind a block can actually be read and reconstructed by anyone. - [Layer 1](https://fudfomo.co/glossary/layer-1): The base blockchain itself, like Bitcoin or Ethereum. The foundation everything else builds on. ## See the full catalogue What The Block! covers more than 2,000 plain-English crypto terms, delivered as embeddable hover-state tooltips for crypto exchanges. https://wtb.fudfomo.co