confusion...

Can someone tell me why variable x is incremented in example 1 but not changed in example 2?

1.
class GFC403 {
private static int x=1;
static void m1(int i) {x++; i++;}
public static void main (String[] args) {
int y=3; m1(y);
System.out.println(x + "," + y);
}}

prints 2,3

2.
class GFC404 {
private static int x=1;
static void m1(int x, int y) {x++; y++;}
public static void main (String[] args) {
int y=3; m1(x, y);
System.out.println(x + "," + y);
}}

prints 1,3