APP_USER

Once a user has been identified, the Application Express engine keeps track of each user by setting the value of the variable APP_USER.

APP_USER

G_USER

From the APEX_APPLICATION package, the global variable G_USER specifies the currently logged in user.

DAD

With an authentication through the database access descriptor (DAD), when Oracle Apex - (Authentication|Identity) equals the value in the Public User field , the Application Express engine considers the current session to be a “public user” session.

From the APEX_APPLICATION package, the global variable G_PUBLIC_USER holds this value.