Accessing vBulletin Membership Data

[MacroPhotoPro]

Okay, sir, this is the feedback my brother was hoping you'd be kind enough to clarify:

Is this the php code I need to use in order to access the primary index that identifies which user is currently logged in?:

// Include global data
include("global.php");

// Grab the current user for future use
$current_user = $vbulletin->userinfo['userid'];

(The security token is a hash code, and not what I am looking for.)

If this is the case, what is the name of the table that stores the user data? I need to know where the data is actually defined in the MySQL database in order to mirror the data type and use for future reference.

Thank you very much for your time!

Jack