In a for loop, the loop variable is initialized to the start value before the loop begins, and then it is incremented or decremented on each iteration until the end condition is reached. By default, the loop variable is initialized to 0 and then incremented by 1 on each iteration. For example: for ($i = 0; $i -lt 10; $i++) { # code to execute } This loop will iterate 10 times, with the loop variable taking on the values 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9. However, you can use any start value and increment/decrement value that you like. For example, you can start the loop variable at 1 and increment it by 2 on each iteration like this: for ($i = 1; $i -le 10; $i += 2) { # code to execute } This loop will iterate 5 times, with the loop variable taking on the values 1, 3, 5, 7, and 9. You can also use a negative increment/decrement value to count down from a higher number to a lower number. For example: for ($i = 10; $i -ge 0; $i--) { # code to execute } This loop will iterate 11 times, with the loop variable taking on the values 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, and 0.