MySQL just makes the terms confusing. The term schema specifically means the collection of tables, views, sequences, etc. The catalog/database (database is the term ANSI SQL prefers, catalog is the term JDBC prefers) is the collection of schemas. MySQL supports no notion of a "collection of schemas"; there is never a time you can open a MySQL connection and refer to objects in other catalogs/databases. Compare that to, say, Oracle or SQL Server where you can refer to both "levels".