Data Availability Sampling (DAS) is a technique used in #blockchain technology to allow users to verify that data is available without needing to download the entire blockchain. This is particularly useful for large blockchains where downloading everything can be impractical. Essentially, users can sample small portions of the data and use these samples to mathematically prove that the complete data exists and is accessible. This helps ensure data integrity and network security without requiring every user to store massive amounts of information.