In most modern computing environments, its just a pointer. If you're doing Win32 or similar, its just a keyword that means nothing.

In older environments, such as MS-DOS, as I recall, a far pointer specifies both the data segment and the offset, whereas a near pointer only stored the offset. In a sufficiently small program, everything was in the same segment and the additional overhead of storing the segment information as well was not necessary.

1. pointer to a constant means you can not change what the pointer points to

2. constant pointer means you can not change the pointer.

Example:

int x; -- integer

int *px= &x; -- pointer to integer

int **ppx= &px; -- pointer to pointer to integer

int ***pppx= &ppx; -- pointer to pointer to pointer to integer

A pointer only holds an address information (location) in the memory.

if a pointer holds points another pointer then it is a pointer to an other pointer.

Pointer holds an address in the memory so in that address there is an other location information that shows another location.

pointer is the variable that holds the address of another variable