a database, removing data structures from the database, modifying the structure of exis1ng data. Update Inser1ng, modifying, and dele1ng data. Retrieval Obtaining informa1on either for end-‐user queries and reports or for processing by applica1ons. Administra)on Registering and monitoring users, enforcing data security, monitoring performance, maintaining data integrity, dealing with concurrency control, and recovering informa1on if the system fails.