What is DDL, DML, DCL, TCL in SQL ?

The Data Definition Language (DDL) includes,

CREATE TABLE - creates new database table

ALTER TABLE - alters or changes the database table

DROP TABLE - deletes the database table

CREATE INDEX - creates an index or used as a search key

DROP INDEX - deletes an index

The Data Manipulation Language (DML) includes,

SELECT - extracts data from the database

UPDATE - updates data in the database

DELETE - deletes data from the database

INSERT INTO - inserts new data into the database

The Data Control Language (DCL) includes,

GRANT – gives access privileges to users for database

REVOKE – withdraws access privileges to users for database

The Transaction Control (TCL) includes,

COMMIT – saves the work done

ROLLBACK - restore the database to original since the last COMMIT