To store and retrieve data, PHP must connect with a database.
Most web applications use MySQL database with PHP.
PHP connects to MySQL using the mysqli or PDO extension.
Here we use mysqli for simplicity.
After connection, PHP should verify whether the connection is successful.
Once connected, PHP can perform database operations such as insert, fetch, update, and delete.
Database connection file is usually kept separate for reuse.
This database connection will be used in all upcoming AJAX CRUD operations.
After completing this lesson, you can connect PHP with database confidently.