What is the use of CUBE in Oracle?

Question

What is the difference between rollup and cupe, which is good to use also give example to solve?
Also if someone can explain about what is grouping function?

Answer 1

The GROUP BY CUBE clause produces a subtotal line for each department number, and calculates a total for each job in each department, a grand total at the end of the query, and a total for each job in the following example. The GROUP BY ROLLUP does not return the totals for each job, but does return everything else like the GROUP BY CUBE.

SQL> SELECT    DEPTNO, JOB, COUNT(*)
     FROMEMP
     GROUP BY CUBE(DEPTNO,JOB);

DEPTNO    JOB      COUNT(*)
---------------------------
10      CLERK      1
10      MANAGER    1
10      PRESIDENT  1
10                   3
20      ANALYST    2
20      CLERK      2
20      MANAGER    1

For More details you can follow: https://oracle-base.com/articles/misc/rollup-cube-grouping-functions-and-grouping-sets