In C programming, a pointer is a variable that stores the memory address of another variable. Pointers are powerful features of C and C++ programming languages, providing the ability to directly interact with memory and manipulate data in a more flexible way.

Key Concepts of Pointers:

1. Memory Address:
   • Every variable in a program is stored in the computer’s memory, and each memory location has a unique address. A pointer holds the address of a variable.
2. Declaration:
   • A pointer is declared with an asterisk (*) before its name. The data type of the pointer must match the data type of the variable it points to. For example, int* ptr; declares a pointer to an integer.
3. Initialization:
   • Pointers are usually initialized with the address of a variable, which is done using the address-of operator (&). For example, ptr = &var; assigns the address of var to ptr.
4. Dereferencing:
   • Dereferencing a pointer means accessing the value at the address stored in the pointer. This is done using the dereference operator (*). For example, *ptr gives the value of the variable whose address is stored in ptr.

#include<stdio.h>
#include<conio.h>

void main()
{
  float x=10;
  float *ptr;
  clrscr();
  printf("\nX=%f",x);
  printf("\nAddress of X=%u",&x); //& address of operator
  //if you know the address then how you can get value on that address
  //Ans. We use Value At Address operator to get address (*)
  printf("\nX=%f",*&x);
  //pointer variable - it is a special variable that can hold address of another variable

  ptr=&x; //address of x stored into ptr

  printf("\nAddress of X=%u",ptr);
  printf("\nValue of X=%f",*ptr);

  *ptr=100;
  printf("\nValue of X=%f",x);
  getch();
}