Oracle Application Express uses a simple architecture where pages are dynamically generated using metadata stored within the Oracle Database. There is no code generation or file based compilation. Once fully installed, a Uniform Resource Locator
(URL) is defined for both developers and end users to access Oracle Application Express.
Users require only a Web browser and the required URL and no additional client software is required.
Oracle Application Express
The Web listener functions as a communications broker between the Web browser and the Oracle Application Express objects in the Oracle database by mapping browser requests into database stored procedure calls.
You have a choice of three Web listeners.
Oracle REST Data Services (formerly Oracle Application Express Listener).
1) The Web Listener receives incoming requests.
2) The Web Listener submits incoming requests in the web request broker for processing.
3) The Oracle data is retrieved and the web request broker builds the HTML or JSP page.
4) Web Request Broker hands the page back to the web listener.
5) The web listener then sends the completed HTML documents back to the originating requester.