For objects that are declared inside the package body, you are restricted to use within that package.
Therefore, PL/SQL code outside the package cannot reference any of the variables that were privately declared within the package.
Any items declared inside the package specification are visible outside the package.
These objects declared in the package specification are called public.
If the variable, constant, or cursor was declared in a package specification or body, their values persist for the duration of the user's session.
The values are lost when the current user's session terminates or the package is recompiled.