What does continue and break exactly do and why does this code get this output? Why is 30 skipped and 10 outputed?

Question

I don't understand why this results in 10 20 and 40. How come 30 is skipped

for(int x=10; x<=40; x=x+10) {
if(x == 30) {
continue;
}
System.out.println(x);
}
/* Outputs
10
20
40
*/

What exactly does continue do exactly fundamently?