What's changed
Celo is moving from being a POS (proof of stake) based L1 blockchain to an L2 built on the OP Stack. In Celo L1 both ordering and data availability were provided by the validators participating in the POS consensus mechanism, being an L2 means that Celo will instead rely on the the L1 (Ethereum) for ordering and on EigenDA for data availability. Outsourcing those components allows Celo to offer increased scalability while focussing on providing value for users. See below for more details about all the changes involved.