DCL or Data Control Language commands are used enforce access control to data within the database or database objects.

These are:

• GRANT <previlige_name> ON <object_name> TO <user_name>
• REVOKE <previlige_name> ON <object_name> FROM <user_name>

DML or Data Modification Language commands are used in creating, updating or deleting data from the database objects such as tables.

These are:

• INSERT INTO TABLE <table_name>
• UPDATE <table_name> SET <column_name>=<new_value>
• DELETE [ <column_name> | * ] FROM <table_name>

DDL or Data Definition Language commands are used in defining or manipulating database schema. These are used for creating, modifying, and dropping the structure of database objects such as tables.

These are:

• CREATE TABLE | DATABASE <object_name>
• ALTER TABLE <table_name>
• DROP TABLE | DATABASE <object_name>