How does Oracle Application Express connect to the database?

I'm mocking up some options for a simple, internal reporting front-end for an Oracle database. I have Oracle XE 11R2 on a separate testing machine, and am going through a tutorial on making a simple report in Application Express. To my surprise, Application Express has magically connected to the XE database. I'm guessing this was so easy because the database and Application Express are on the same machine. However, I'm wondering how this would work in a production/network environment. My former solution was an MS Access front-end, which used an ODBC connection to connect to the database. But I don't imagine Application Express would use an ODBC connection. How does Oracle Application Express connect to the database in a production/network environment? Would an equivalent to an ODBC connection need to be deployed on each machine that uses the Application Express report? ----------------------- *Note: I'm well aware that I have no idea what I'm doing. I'm just trying to get a grasp on how this all works, so I can make an informed pitch to my I.T. department. Corrections are welcome.*