explain what exactly a pointer do?

Answer 1

A pointer contains the address of a variable at witch it points
And to declare a pointer use the *
Ex: int* p; a pointer for a int
Double*p; a pointer for a double

If you cout<<p ; it will give you the address in a hexadecimal number

If you want a pointer to point at a variable called a you do as follows
Int a;
Int *p;
p=&a

Where &a is the address of a in the memory

Now if you wanna print the value of a pointer you also use the * but in a diffrent syntax

Cout<<*p ;
It will give you the value of the variable
In this example it will give you the value of a ;

Answer 2

a variable used to store an address of another variable...

Answer 3

it points to a variable , so if you change the value of a pointer , it will change the value of the varible it is pointing too