Data Definition Language(DDL) :

Data Definition language is used for creating database structure or database schema.
There are many DDL commands in Sql.

1-Create : Create command is used to create database.

2-Alter : Alter Command is used  for altering  database or table structure.

3-Truncate : Truncate  command is used to delete all data from database table.It delete all data   with     blank space .

4-Comment: Comment command are used for add comments to data dictionary.

5-Rename: Rename command are used for rename object name.

Data Manipulation Language(DML) :

DML is used for insertion,deletion,updation and managing information or data  from the database schema or database objects.

There are lots of DML commands in sql :--


1-Insert : Using insert command we can insert data into database object or database table

2-Update :Using update command we can update existing  data into database object or database table

3-Delete : With the help of delete command we can delete data from the database object or table.

4-Select : Select   command is  used to retrieve data from the database objecte or table.