There are many practical reasons to capture an image of your screen.
Have you ever had a weird message appear on your iPhone? Or saw a Facebook post with a clever quote that you want to save? Or maybe you've taken a great video and would like to capture a still shot from the action? Learning how to take a screenshot allows you to capture an image of exactly what you are seeing on your iPhone.
Here's how to take a screenshot on your iPhone:
Press and hold the sleep/wake button on the upper right side of your iPhone.
Simultaneously press and release the Home Button (bottom middle of your iPhone).
You'll hear the camera shutter sound when the picture is taken.
The photo will appear along with all other photos you take and also be located in the Screenshot album of your Photos app.
If you're not taking screenshots, give it a try! I'm sure you'll find many uses.