
Taking a screenshot is all well and good, but more often than not you don’t actually need the whole screen in the capture. On Macs there’s a simple way to grab just the part of the screen you want: Cmd + Shift + 4.
From there, click and drag out a box over the part of your screen you wish to capture. Upon release the image will be saved to the desktop. If you do just want to grab the whole screen, press Cmd + Shift + 3 instead.