nested Procedure

In general, something that is nested is fully contained within something else of the same kind.

In programming, nested describes code that performs a particular function and that is contained within code that performs a broader function.

One well-known example is the procedure known as the nested do-loop .A Procedure  within a  Procedure  is a nested  Procedure.

DECLARE
      PROCEDURE P2;   --  forward declaration
      PROCEDURE P3;    --  forward declaration
      PROCEDURE P1 IS
      BEGIN
         dbms_output.put_line('From procedure p1');
         p2;
      END P1;
      PROCEDURE P2 IS
      BEGIN
         dbms_output.put_line('From procedure p2');
         p3;
      END P2;
      PROCEDURE P3 IS
      BEGIN
         dbms_output.put_line('From procedure p3');
      END P3;
BEGIN
     p1;
END;

Output:-
From procedure p1
From procedure p2
From procedure p3