Final answer:
A MySQL connection in PHP does not automatically close when the script ends. It is necessary to explicitly close the connection using the mysqli_close() function to prevent resource leaks and optimize performance.
Step-by-step explanation:
A MySQL connection in PHP will not automatically close when the script ends. It is important to explicitly close the connection to the MySQL server after the script has finished executing. This can be done using the mysqli_close() function in PHP.
Leaving the connection open without explicitly closing it can lead to resource leaks and can affect the performance of the application.
Here is an example of how to close a MySQL connection in PHP:
<?php
$connection = mysqli_connect('localhost', 'username', 'password', 'database');
// ... your code ...
mysqli_close($connection);
?>