What is this code in my functions.php

Hi,

Very long ago I had put the below code in my child theme's functions.php. I don't have any idea of what it is. Can anyone tell me,what is it?

<?php

add_filter('admin_title', 'my_admin_title', 10, 2);

function my_admin_title($admin_title, $title)
{
		return get_bloginfo('name').' &bull; '.$title;
}

Thanks