What is the difference between data definition operations and data manipulation operations in SQL?

SQL operations are divided into two main categories:

1. Data Definition Language (DDL) — commands that create, modify, or delete the structure of a database. For example:

   • CREATE (creating tables, databases)
   • ALTER (modifying table structures)
   • DROP (deleting tables or databases)

2. Data Manipulation Language (DML) — commands that work with the contents of tables, i.e., the data itself. For example:

   • SELECT (reading data)
   • INSERT (adding new records)
   • UPDATE (updating existing records)
   • DELETE (removing records)

Thus, DDL manages the database structure, while DML manages the data.