Cursors that are used in PL/SQL are of two types:

1. Implicit cursor
2. Explicit cursor

Implicit Cursor

PL/SQL declares an implicit cursor for every DML command, and queries that return a single row.  The name of the implicit cursor is SQL.  It can be used directly without any declaration. 

Explicit cursor
Explicit cursors are SELECT statements that are Declared explicitly in the declaration section of the current block or in a package specification. Use OPEN, FETCH, and CLOSE in the execution or exception sections of the programs. The following example uses a cursor to select the five highest paid employees from the emps table.

ENAME                     EMPNO        SAL
-------------------- ---------- ----------
kavitha                        17      20000
deepa                           8      15000
kala                            15      15000
subha                          9      15000
shobana                      27     10000

Cursor example

Create the table named as temp
SQL> create table temp (my_sal number (5), my_empno number (5), my_ename varchar2 (20));

Table created.

SQL>

  1 DECLARE
  2     CURSOR c1 is
  3        SELECT ename, empno, sal FROM emps
  4           ORDER BY sal DESC;
  5     my_ename CHAR (10);
  6     my_empno NUMBER (4);
  7     my_sal   NUMBER (7,2);
  8 BEGIN
  9     OPEN c1;
 10     FOR i IN 1...5 LOOP
 11        FETCH c1 INTO my_ename, my_empno, my_sal;
 12        EXIT WHEN c1%NOTFOUND;
 13        INSERT INTO temp VALUES (my_sal, my_empno, my_ename);
 14        COMMIT;
 15     END LOOP;
 16     CLOSE c1;
 17* END;
SQL> /

PL/SQL procedure successfully completed.

SQL> SELECT * FROM temp ORDER BY my_sal DESC

    MY_SAL   MY_EMPNO MY_ENAME
---------- ---------- --------------------
     20000         17 kavitha
     15000          8 deepa
     15000         15 kala
     15000          9 subha
     10000          27 shobana