How does PHP handle closing database connections at the end of a script execution, especially when retrieving data from multiple tables?

When retrieving data from multiple tables in PHP, it is important to properly close the database connection at the end of the script execution to free up resources and prevent potential issues such as running out of available connections. One way to ensure this is by using the `mysqli_close()` function to explicitly close the connection after all database operations have been completed.

// Perform database operations to retrieve data from multiple tables

// Close the database connection at the end of the script execution
mysqli_close($connection);