You can easily share what's on your screens by taking screenshots. Hardware buttons let you snap a screenshot and store it locally. Afterwards, you can view, edit, and share the screen shot in Photos or a similar app.
Method 1: Push the power button and Volume down button at the same time for a couple of seconds.
Method 2: Swipe down to access the quick settings from any screen, and then click the screenshot icon to take a screenshot.
You should then see an animation showing you the screenshot, and view the screenshot by tapping on the thumbnail in the notification tray or by visiting your Photos application.