I presume you mean a pointer to a pointer, and not a pointer to a double type. Here's a non-programming example: You ask me for contact information for a plumber. I point you to the phone book. The phone book points you to the plumber. A programming example would be a 2D pseudo-array gotten from the heap one row at a time. To access a given element, one would provide a pointer to the row pointer, which would then be dereferenced to get the element.
