A Data Definition Language or Data Description Language ( DDL ) is
a computer language for defining data structures.

Examples of DCL commands include: create/drop/alter

Data Manipulation Language ( DML ) is a family of computer languages
used by computer programs and/or database users to insert, delete and update
data in a database.

Examples of DCL commands include: insert/delete/select/update

Data Control Language (DCL) is a computer language and a subset of SQL, used
to control access to data in a database.

Examples of DCL commands include: grant/revoke