DDL (Data Definition Languages) statement: the database definition statement
Used to create tables, indexes, views, stored procedures, triggers, etc. in the database, commonly used statement keywords are: CREATE, ALTER, DROP, TRUNCATE, COMMENT, RENAME.
DML (Data Manipulation Language) statement: the data manipulation statement
Used to query, add, update, delete, etc., commonly used statement keywords are: SELECT, INSERT, UPDATE, DELETE, MERGE, CALL, EXPLAIN PLAN, LOCK TABLE, including general additions, deletions, and changes.
DCL (Data Control Language) statement: the data control statement
Used to authorize/revoke the permissions of the database and its fields (DCL is short name of Data Control Language which includes commands such as GRANT and mostly concerned with rights, permissions and other controls of the database system.). Commonly used sentence keywords are: GRANT, REVOKE.
TCL (Transaction Control Language) statement: transaction control statement
Used to control transactions, commonly used statement keywords are: COMMIT, ROLLBACK, SAVEPOINT, SET TRANSACTION.
Reference
https://www.cnblogs.com/heyonggang/p/9284271.html