Until Windows 10, the Snipping Tool remained unchanged since it was introduced in Windows Vista. In Windows 10, the Snipping Tool has all the same features as before, but also adds the ability to take a delayed screenshot. If you click the down arrow next the "Delay" button, you'll see that you can pick a number between 0 and 5. This number represents how many seconds the Snipping Tool will wait between the time you click "New" and the time the actual screenshot is taken. This gives you time to do things like open menus in a window, since when you click over to the Snipping Tool menus in other windows are likely to close.