This is my favourite of the Mac goodies. There are a few ways to capture screen on Mac.
Firstly, you can capture the whole screen. Simply press Cmd-Shift-3 on your keyboard and the screen will be captured in a PNG file and saved on your desktop as something like Picture 1.png
You can also capture a selection, just press Cmd-Shift-4 on your keyboard and you will see a small cross hair selector on your screen.
Simply select the area you want to capture and let go, the file will be saved on your desktop, again something like Picture 1.png
And finally you can capture the active window. Simply follow the steps above and once you see the cross hair, press the space bar and you will get a camera icon. Hover the camera above any window and the window will get the gray overlay indicating it’s in hot-spot. Click on it and the window will be captured.
And again, the file will be safely placed on your desktop as … good guess, Photo 1.png
However, if you’d like to capture the screen (or part of it) to the clipboard rather than to desktop, simply hold the Control key down while capturing, i.e. Shift-Ctrl-Cmd-4.
This is very handy when you need to paste it straight into an email or any other document.