Thread: what's difference between global and static variable declare outside function

Hi,
I am little bit confused I don't understand difference between global variable and static variable that declare outside function.

Code:

#include<stdio.h>

int X = 10;  //Global variable 
static int Y = 100; // static variable 


int main ()
{
	while (1)
	{
		return 0;
	}
	
}

Both X and Y variable are only accessible within source file
Both X and Y variable only alive until program exit

I don't understand difference between global variable and static variable that declare outside function.

Is there any difference between them in standard c ?

Are they same or different?