just basically loops through a specified number, example:
if you would like to count to ten, but not have to keep writing:
System.out.println("1");
System.out.println("2");
//etc
then you would simply do:
for (int i = 0; i <= 10; i++) { //defining an int, starts at 0; the int is less than or equal to 10; everytime code below is complete, int goes up by 1 and repeat until the int has reached its max var (this case being 10).
System.out.println(i); //printing out the number
}