If you're using a Macbook with a Touch bar, you can press Cmd + Shift + 4 to enter a screenshot selection mode, and then use Touch bar to adjust screenshot mode (full screen, window or selection) and destination (Desktop, Clipboard, Preview, Documents etc) on the fly.
If you're using a Macbook with a Touch bar, you can press Cmd + Shift + 4 to enter a screenshot selection mode, and then use Touch bar to adjust screenshot mode (full screen, window or selection) and destination (Desktop, Clipboard, Preview, Documents etc) on the fly.