A database is an organised collection of related data; a DBMS is the software that stores, retrieves and protects it.
1Key ideas
Three-schema architecture: physical, logical (conceptual) and view (external) levels
Data independence: physical and logical
Languages: DDL (CREATE, ALTER, DROP), DML (SELECT, INSERT, UPDATE, DELETE), DCL (GRANT, REVOKE), TCL (COMMIT, ROLLBACK)