What is pointers and its uses?

Pointer is a variable which holds the address of the another variable.
for ex:int *p;
here p is a pointer which holds the address of inter variable.
uses of pointers:
1.To access array elements
2.Pointers use in dynamic memory allocation linked linked lists,trees,graphs.
3.Passing data in & out of without coping .
4.Create and manage your own data types.