Update with Cursor in Oracle

I have several doubts about the use of cursors in ORACLE especially to update records, in several places I read that the declaration of the cursor is done with the CURSOR parabra in the declare, but in my work they have declared cursors in Stored Procedures in the section AS as follows:

create or replace PROCEDURE sp_xyz(
    v_pcFecInicial IN DATE,
    v_pcFecFinal   IN DATE,
    v_vSuma        IN NUMBER,
    v_vcUsr_actual IN CHAR
    ) AS vcMLista SYS_REFCURSOR;
BEGIN

Likewise, it is used:

CURSOR nombre_cursor [ (parámetro [, parámetro, …]) ] IS
SELECT

To declare the cursor and in my work we use:

open vcMLista for
     SELECT actm_lista.num_entrada , ....

Which of the two syntaxes is the correct one?