The Linux distribution Ubuntu has a built-in functionality for creating screenshots and screencasts.
To take a screenshot of the entire screen, use the key PrtScr, most often it is located to the right of F12 and can also be called on the keyboard "PrtScn", "PrntScrn", "Print Scr".
To take a snapshot of the active program window, press Alt + PrtScr.
To capture the desired area of the screen, press the key combination ⇧ Shift + PrtScr.
To create a video from the screen (the so-called screencast), simultaneously hold down the keys Ctrl + Alt + ⇧ Shift + R.
To stop recording video, use the keyboard shortcut again Ctrl + Alt + ⇧ Shift + R.
By default, captured videos will be saved in the "Videos" folder.