What happens when you login to Apps

Firstly and surely there is a URL for Oracle Applications that is structured possibily in below format, possibly in below format, although it can vary from version of apps.

http://machinename:portnumber/OA_HTML/US/ICXINDEX.htm
http://machinename:portnumber /oa_servlets/AppsLogin

When you join an Oracle Applications development team for an employer, you will first be given URL of the development environment.

In any Oracle Applications Implementation project (assuming it has gone live, there are minimum of three environments, each with three different URL's and different database instances.

These are:-

1.Development Instance
2.Testing Instance
3.Production Instance

As a techie, you will be given URL, User Name and Password of the development environment.

What happens when you login?

1.Your login gets authenticated against the table named fnd_user for
your username and password. This is called user definition screen.
Only System Administrator have access to this. The screen below is
where username and password is defined.

2.As you can see below, this username=MANNAMALAI is attached to
responsibilities. It is this assignment to the responsibility that
controls what a logged in person can do and can't do. In layman's
words, a responsibility is a group of menu.