V$PARAMETER2 displays information about the initialization parameters that are
currently in effect for the session, with each list parameter value appearing as a row in
the view. A new session inherits parameter values from the instance-wide values
displayed in the V$SYSTEM_PARAMETER2 view.
Presenting the list parameter values in this format enables you to quickly determine
the values for a list parameter. For example, if a parameter value is a, b, then the
V$PARAMETER view does not tell you if the parameter has two values (both a and b)
or one value

We all know that v$parameter shows the parameter files of current instance.
And v$parameter2 shows the parameter files of the whole Database.

V$PARAMETER displays information about the initialization parameters that are currently in effect for the session.

$PARAMETER2 displays information about the initialization parameters that are currently in effect for the session, with each list parameter value appearing as a row in the view.

Then when i fire the below command, it shows both of the above mentioned view is having same parameters.

SQL> select name from v$parameter
  2  intersect
  3  select name form v$parameter2;
select name form v$parameter2
                 *
ERROR at line 3:
ORA-00923: FROM keyword not found where expected