Images of the computer screen are best recorded as "screen shots".
A screenshot is a photo-like picture of the contents of your computing device screen, whether PC, Mac, Chromebook, tablet, or smartphone, and will typically be saved to your desktop or photos as screenshot.jpg. This image can then be edited and inserted into documents like any other digital image.
The exact procedure for taking a screenshot depends on the device.
(1) MacBook Air
There are two types of screenshots on a Mac computer.
Command Key +Shift + 3 takes a screenshot of the entire desktop
Command Key +Shift + 4 produces a small + shaped cursor, which is then used to highlight a selected portion of the screen.
See https://support.apple.com/en-us/HT201361 or https://www.businessinsider.com/how-to-screenshot-on-mac for a more detailed description.
(2) Screenshots on a PC
How to take a screenshot on Windows 10 with the PrtScn key
Press PrtScn. This copies the entire screen to the clipboard. ...
Press Alt + PrtScn. This copies the active window to the clipboard, which you can paste into another program.
Press the Windows key + Shift + S. ...
Press the Windows key + PrtScn.
Mouse and keyboard
To open Snipping Tool, select the Start button, type snipping tool, and then select it in the search results.
To choose the type of snip you want, select Mode (or, in older versions of Windows, the arrow next to New), and then choose Free-form, Rectangular, Window, or Full-screen Snip.
https://support.microsoft.com/en-us/help/4027213/windows-10-open-snipping-tool-and-take-a-screenshot
(3)Take a screenshot on your iPhone
Press the Side Button and the Volume Up button at the same time.
Quickly release both buttons.
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.
(4) To take a screenshot on a Chromebook:
View the site you're experiencing difficulty with.
Press Ctrl + Show windows . (For non-Chrome OS keyboards, press Ctrl + F5.) Your screenshot is saved as a PNG file in your "Downloads" folder.