In Windows 10 and 11, you can use Windows' own “Snipping Tool” to take screenshots.
To do this, press the ‘Windows logo key’, ‘Shift’ and ‘S’ at the same time. This will display a crosshair with which you can select a desired screen section by holding down the left mouse button.
This is automatically copied to your clipboard so that you can paste it into any programme, or even into an e-mail.
It is also displayed in the ‘Snipping Tool’ itself so that you can edit and save it there.
Alternatively, and also in older versions of Windows, you can press the ‘Alt Gr’ and ‘Print (Print Scr)’ keys simultaneously to copy an image from an open, visible programme window to your clipboard.