To take a screenshot on a Mac, you can use the following keyboard shortcuts:

  1. Entire Screen: Press Shift-Command-3 to capture the entire screen. The screenshot will be saved as a file on your desktop.

  2. Portion of the Screen: Press Shift-Command-4 to turn your pointer into a crosshair. Move the crosshair to where you want to start the screenshot, click and drag to select the area, and then release the mouse or trackpad button. You can press the Escape key to cancel taking the screenshot at any time.

  3. Window: Press Shift-Command-4 and then the Space bar. This will change the pointer to a camera. Move the camera over to the window or menu you want to capture, which becomes highlighted to confirm that it's selected. Then click to take the screenshot.

  4. Touch Bar (MacBook Pro): Press Shift-Command-6 to capture the entire Touch Bar.

Additionally, you can use the built-in Screenshot app by pressing Shift-Command-5. This app offers more options, including recording the screen and setting a timer delay.

If you want to copy the screenshot to the clipboard instead of saving it as a file, add the Control key to the shortcuts. For example, Shift-Control-Command-3 will copy the entire screen to the clipboard.