Oracle Exam 1Z0-770 Topic 1 Question 1 Discussion

APP_USER is a built-in substitution string in Oracle APEX that stores the user name of the current user session. The APEX engine uses APP_USER as one component of a key for tracking each user's session state. As a user navigates from page to page, the APEX engine sets the value of APP_USER to identify the user. The APEX engine also uses APP_USER to perform security checks and conditional processing. You can reference APP_USER using different syntax depending on the context, such as SQL, PL/SQL, or static text.