Celestia is a modular data availability (DA) network that securely scales with the number of users, making it easy for anyone to launch their own blockchain.
Rollups and L2s use Celestia as a network for publishing and making transaction data available for anyone to download. For them, Celestia provides high-throughput DA that can be verified easily with a light node. And by making the blockchain stack modular, anyone can launch their own blockchain without needing a validator set. Data availability sampling (DAS) is the new primitive that enables Celestia light nodes to verify DA efficiently. Instead of downloading all data, light nodes only download a tiny portion of each block.