Difference between DDL, DML and DCL,TCL commands?

Data Definition Language (DDL):

CREATE - to create objects in the database 

ALTER - alters the structure of the database 

DROP - delete objects from the database 

TRUNCATE - remove all records from a table, including all spaces allocated for the records are removed 

Data Manipulation Language (DML): 

SELECT - retrieve data from the a database 

INSERT - insert data into a table 

UPDATE - updates existing data within a table 

DELETE - deletes all records from a table, the space for the records remain 

Data Control Language (DCL) : 

GRANT - gives user's access privileges to database 

REVOKE - withdraw access privileges given with the GRANT command

Transaction Control (TCL) :

COMMIT - save work done 

SAVEPOINT - identify a point in a transaction to which you can later roll back 

ROLLBACK - restore database to original since the last COMMIT 

SET TRANSACTION - Change transaction options like isolation level and what rollback