Memory allocation. Pretty simple, but I guess there might be some people here who do not know what it is...
#include<stdio.h>
#include<iostream.h>
int main()
{
int *n = new int;
*n=12;
printf("n's value is %d\n",*n);
*n=25;
printf("n's value is %d\n",*n);
delete n;
printf("n was deleted\n");
system("PAUSE");
return 0;
}