What is the difference between stdin and STDIN_FILENO?

Question

What is the practical difference, if any, between stdin and STDIN_FILENO in C?

Answer 1

stdin : 1. A file pointer (* FILE) 2. The file descriptor table holds its address when process is created. 3. present in /usr/include/stdio.h

STDIN_FILENO : 1. It is a macro 2. Its nothing but an array index of a file descriptor table (default 0). 3.present in /usr/include/unistd.h

Could be more clear by following code.

#include 
#include 
int main() 
{    
     printf("%d\t\t%p ----- ",STDIN_FILENO,stdin);

return 0; 
}