Step #1: Open the screen you want to screenshot.
Step #2: Press the volume down and power button of the device at the same time.
Step #3: Press and hold until the shutter sound is heard.
Step #4: You will see the thumbnail preview image when the device takes a screenshot.
Step #5: You can edit the screenshot by tapping this image.
You can access the screenshot you have taken from your gallery or via Google Photos.