Ethereum is transitioning from a monolithic blockchain to a modular ecosystem, where execution, consensus, settlement, and data availability are split across specialized layers. Monolithic blockchains (e.g. Bitcoin, early Ethereum) operate on a single layer, requiring every node to process execution, consensus, and data storage in one go. By contrast, modular architectures decouple these functions: separate execution layers (Layer 2 rollups), a consensus/settlement layer (the Ethereum base), ...
