MySQL Error! Help mysqli_connect 2800/1045

We seem to be getting an error on my website when trying to load it up. Here is the error:

Warning: mysqli_connect(): (28000/1045): Access denied for user 'admin'@'localhost' (using password: YES) in /home/u616069576/public_html/inc/database.php on line 9 Failed to connect to MySQL: Access denied for user 'admin'@'localhost' (using password: YES) Warning: mysqli_query() expects parameter 1 to be mysqli, boolean given in /home/u616069576/public_html/login.php on line 12 Warning: mysqli_error() expects parameter 1 to be mysqli, boolean given in /home/u616069576/public_html/login.php on line 12

This brings the question of which password should I use?

The one that I log into PHPMyAdmin with or the one listed on the User section of PHPMyAdmin. I haven't much experience, so any help would be greatly appreciated.