DDL stands for Data Definition Language, which is used to define and manage the structure of the database. It includes commands like CREATE, ALTER, and DROP, which are used to create, modify, and delete database objects like tables, indexes, and constraints.
DML stands for Data Manipulation Language, which is used to manipulate and query the data stored in the database. It includes commands like SELECT, INSERT, UPDATE, and DELETE, which are used to retrieve, insert, update, and delete data from tables.
Therefore, the correct answer is DDL and DML as these are the two parts of SQL that deal with defining and managing the structure of the database and manipulating and querying the data stored in the database, respectively.