What is pointer & how it uses in c program ?

Answer 1

A pointer is a variable which stores the address of another variable.We can have pointer to any data type or in fact we can have pointers to functions as well.
The address of the variable can be accesses by the & operator.

int a = 10;
printf("address of a : %p\n", &a);

You can store this address in a pointer like
int *p = &a;

printf("address of a : %p\n", p);

Answer 2

thank you sir @Rajat Paluwal