What's the difference between data definition language and data description language?
DDL (Data Definition Language): Used for defining data structures and schema like CREATE and ALTER commands.

DML (Data Manipulation Language): Used for managing data with schema objects like SELECT commands.

DCL (Data Control Language): Used to control data like REVOKE and GRANT commands.

TCL (Transaction Control Language): Used to manage the changes made by DML statements like COMMIT.

Reference Link