MacMost: Screenshots

The Complete Guide To Taking Screenshots On a Mac
A single keyboard shortcut will take you to a power control that will let you take a screenshot of your entire screen, a window or an area. You can set options such as where to save the screenshot or which app to send it to. You can also use the floating thumbnail feature to preview and edit a screenshot before you do anything with it. A variety of hidden keyboard shortcuts make taking screenshots faster and easier if you take the time to learn them.