Global Variables

Global Variables remains same for the session.

But using of parameter is recommaned compared to usage global variables.

e.g:

create or replace package glob as
procedure G_var;
end;

Create or replace package body as
g1 varchar2(10):='Global Variable';--Global varable declaration
procedure g_var as
begin
dbms_output.put_line(g1);
if g1='Global Variable'
then
g1:='Executed Global Varable';
dbms_output.put_line(g1);
end;
end;

now when u execute this package as glob.g1 the output will be Global Variable and Executed Global Variable.

In forms u can call a global variable in pre form and when-new form instance trigger:

:GLOBAL. := null;
in when new form tigger
:Global.Application_id:='PROD';