Personal Computer:
How to take a screenshot from a PC?
The simplest way to take a screenshot in Windows is to use the Print Screen button. You'll find it on the upper-right side of most keyboards. Once you have hit "Prt Scr" you have to open Word, Paint or some other image editing program to view, edit or save the image. For example, open Word and click Ctrl and v on the keyboard for pasting your image. This is a shortcut instead of right-clicking the mouse and selecting paste.
Windows also offers Snip & Sketch, Shift+Windows Key+S keyboard shortcut, which will launch a small toolbar at the top of the screen so you can easily choose what to capture.Snipping Tool is a program that is included for free with Windows 7 and upwards.
Mac
When using Mac, pressing the "Command, Shift and 3" keys together will take a screenshot of your entire screen. This screenshot will be automatically saved to your desktop.
Press the "Command, Shift and 4" keys together to take a screenshot of a selected area. The captured image will be saved as “picture” on the desktop.
Android Phone:
Press and hold the "power and volume-down buttons" for a couple of seconds. Pull down the notification panel and tap the "Capture+ icon" or "screen shot" or "screen capture" icon.
iPhone:
Press the "side button and the volume up button" at the same time.
After you take a screenshot, a thumbnail temporarily appears in the lower-left corner of your screen. Tap the thumbnail to open it or swipe left to dismiss it.
To view the screenshots: Open Photos, then go to Albums > Screenshots.