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.
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).