java. Can you explain me the following code?

the output is

5 7 9

3 6 8

public class TwoDimensionalArrays {

public static void main(String[] args) {

int[][] x = {{5, 7, 9}, {2, 5, 7}};

for (int i = 0; i < x.length; i++) {

for (int j : x[i]) {

System.out.print((i + j) + " ");

}

System.out.println();

}

}

}