Internal Login Flow in Oracle Apps

1.DB connection is established using APPLSYSPUB user.
This user “APPLSYSPUB” is having access to fnd_user view and a small set of other public tables needed to establish the initial connection.
2.Once DB connection is established FND_USER table is used to get ENCRYPTED_FOUNDATION_PASSWORD.
3.Using GUEST/ORACLE password combination and ENCRYPTED_FOUNDATION_PASSWORD  string obtained from 2 above,
 we get Apps schema password.
4.Internally it tries to connect to Apps schema with the password retrieved in step 3 above.
If the connection fails, then
   a)The GUEST username password is incorrect
   b)The FNDNAM (APPS) environment variable is set incorrectly.
   c)Some other problem prevented a connection
5 Using Apps password obtained in Step 3 and ENCRYPTED_USER_PASSWORD string from FND_USER table, password for Application user (e.g. SYSADMIN) is obtained.
6. The Application user password obtained in Step 5 is compared to the application user password entered by user in login screen. If both passwords match then user is allowed to get into self-service.
7. A list of responsibilities assigned to that user is shown.
 The user picks one of the responsibilities listed.
8. Each responsibility has a data group and application defined for it.Together, the data group and application define the Oracle account the responsibility uses.