C : Programming Language

Pointers:

"A pointer is a variable that contains the address of a variable."
The C Programming Language, Second Edition, Dennis M. Ritchie.

Lets see in this example.

#include <stdio.h>
int main() {
int a, *pointer;

//store a value in 'a'
a = 10;

//store the address of 'a' in 'pointer'
pointer = &a;

//print value of 'a'
printf("value of 'a' = %d\n", a);

//print value of 'pointer'
printf("value of 'pointer' = %p\n", pointer);

//print value stored at the address which is stored in 'pointer'
printf("value stored at the address which is stored in 'pointer' = %d\n", *pointer);

//print address of 'a'
printf("address of a = %p\n", &a);
}

Output:

value of 'a' = 10
value of 'pointer' = 0x7fff580fbb5c
value stored at the address which is stored in 'pointer' = 10
address of a = 0x7fff580fbb5c

Explanation:

See the first in the code.
int a, *pointer;

Here two variables are declared: a and pointer but before variable pointer there is an operator '*'. This operator '*' makes the variable pointer as pointer else this variable has no difference than a.

In next line, we are storing value 10 in variable a and then we are storing the address of variable a in variable pointer in next line. Operator & returns the address of any variable. Then in consecutive lines we are printing the values.

Operators: & and *