There are four significant subsets of the Structured Query Language (SQL): Data Definition Language (DDL), Data Manipulation Language (DML), Data Control Language (DCL), Transaction Control Language (TCL). DDL defines the structure of the table in the relational database. It consists of commands like ALTER, CREATE, DROP, etc. DML is used to manipulate or update an existing database with commands like SELECT, INSERT, UPDATE, etc. DCL controls the access levels to the database by different users in the organization using GRANT and REVOKE. TCL deals with transactional operations like ROLLBACK, COMMIT, SAVEPOINT, etc. These languages help us to perform different complex operations on the relational database.