A for loop is a loop that can run a set number of times. For example, you could use a for loop with a counter to repeat a set of instructions 10 times. Or you could use a for loop to cycle through every letter in a string or every element in an array (see the next tutorial). Every repetition of the loop is called an iteration.
Watch the video below and then scroll down to view the code.
Take a look at the sample code below which shows how to use a counter in a for loop.
Next tutorial: Looping through arrays (and strings)