To take a screenshot on a Mac, there are several keyboard shortcuts that can be used depending on whether you want to capture the entire screen, a portion of it, or a specific window:

• Press Shift + Command + 3 to capture the entire screen. The screenshot is saved automatically to your desktop.
• Press Shift + Command + 4 to capture a selected portion of the screen. This turns the cursor into a crosshair, which you can drag to select the area to capture. Release the mouse or trackpad button to take the screenshot.
• After pressing Shift + Command + 4, press the Spacebar to change the crosshair into a camera icon. Then click on any open window to capture a screenshot of that window.
• Press Shift + Command + 5 to open the screenshot toolbar, which gives you options to capture the entire screen, a specific window, or a selected portion, as well as options for screen recording.
• On MacBooks with a Touch Bar, press Shift + Command + 6 to take a screenshot of the Touch Bar.

Screenshots usually appear as thumbnail previews in the bottom-right corner, which you can click to edit, share, or save. By default, screenshots are saved to the desktop, but the location can be changed in the screenshot toolbar options (Shift + Command + 5).