A for loop written, or “nested”, inside of another for loop. For example: ``` for(int i = 0; i < 5; i++){ for(int j = 0; j < 3; j++){ System.out.println(i + " " + j); } System.out.println(""); } ``` This would print out: ``` 0 0 0 1 0 2 1 0 1 1 1 2 2 0 2 1 2 2 3 0 3 1 3 2 4 0 4 1 4 2 ```
