I am pretty handy with SQL on a networked system where all users have the same access, and in fact no real log on at all, just a company network.

I have an application that will run on an internet server where some users will be maintaining their own data and of course I only want them to have access to it, and not users with the same privledge to their own data. The data will ultimately be used by normal users that won't log on at all just access the data as they wish for viewing.

I just need a start in how to structure the data and where does the log in data go?

This is what I want to do.
<?
$connection = mysql_connect("yourHostName", "Username", "Password") or die ('cannot reach database');
$db = mysql_select_db("DatabaseName") or die ("this is not a valid database");
?>

Once that user logs on, I will know what data they should have access to...

In this example, where is "Username" and "Password" stored?