Well this might seen like an impossible thing to do but actually, once you know how, it is pretty simple. This can be really useful if you want to write instructions about something or if you just want to email what you can see on your phone to someone else. In any case there are many reasons why you may want to take a screenshot on your iPhone!
So, all you need to do, once you have the screen that you want a picture of, is to hold down the power button on the top of the phone and at the same time press the ‘home’ button that is the circular one on the front of the phone at the bottom. This will save the screenshot to your camera roll.