To take a screenshot on an Samsung Galaxy Sol 3 phone, you must press the Power key and the Volume down button at the same time.
For Samsung phones, there is an original way to take a screenshot, this is to hold the edge of your hand across the phone screen from left to right.
As a result, your screenshot will be saved to the gallery. This screenshot can be used to share it on social networks, instant messengers or keep it as a photo.