Why use double pointer? or Why use pointers to pointers?

Question

When should a double pointer be used in C? Can anyone explain with a example?What I know is that a double pointer is a pointer to a pointer. Why would I need a pointer to a pointer?

Answer 1

One reason would be to pass a 2-D array as a parameter....

Another is to DYNAMICALLY allocate memory for a 2-D array, because the dimensions required

are not known until run time.

I will post a C program that illustrates these concepts