What is the difference between DDL, DML, DCL, and TCL?

These are categories of SQL commands:

DDL (Data Definition Language): Defines database structure

• Commands: CREATE, ALTER, DROP, TRUNCATE
• Example: CREATE TABLE users (id INT PRIMARY KEY, name VARCHAR(50));

DML (Data Manipulation Language): Manipulates data within tables

• Commands: SELECT, INSERT, UPDATE, DELETE
• Example: INSERT INTO users (id, name) VALUES (1, 'John');

DCL (Data Control Language): Controls access to data

• Commands: GRANT, REVOKE
• Example: GRANT SELECT ON users TO user_role;

TCL (Transaction Control Language): Manages transactions

• Commands: COMMIT, ROLLBACK, SAVEPOINT
• Example: COMMIT; or ROLLBACK;