Macro in Teradata

What is macro. What is the difference between macro and procedure.

A macro is the set of sql statements which can be run as a single statement.
          Macro                                                                    Procedure
Macro returns set of data/rows to the user.     It does not return data/rows to the user.
It is allows only input values.                            It provides Input/Output parameter.
It is stored in DBC Perm space.                    It is stored in DATABASE/USER Perm space.

To create a macro:

CREATE MACRO macro_name AS
(SELECT eid, ename  FROM emp WHERE deptno=20;);
 To execute a macro:
 EXEC macro_name; 

To create a parametrized macro:
CREATE MACRO macro_name( in_param DATATYPE)
(SELECT eid, ename  FROM emp WHERE deptno= :in_param;);
To execute a macro:
EXEC <macro_name> [parameter value list];