DDL stands for Data Definition Language, which is a subset of SQL and a part of DBMS (Database Management System) . DDL commands are used to create, modify, and delete database structures but not data. These commands are used to define the components of databases using Database Management Systems. DDL commands define the table structure and its column properties. Some examples of DDL commands include CREATE, ALTER, TRUNCATE, and DROP. These commands are used to create or modify the database objects like tables, views, etc. . DDL is also used to define the storage groups, different structures, and objects in a database. When a DDL statement is executed, it takes effect immediately in the database. DDL is sometimes known as Data Description Language since its statements can also be used to describe, comment on, and place labels on database objects.