Shut Down window

From Mac Guides

The main Shut Down Window allows you to Shut Down your Mac (the default) or also choose Restart, Sleep, or Cancel. This window can be called up by pressing the power button on some Macs, especially portables, or on older Macs with a power button/restart button on the keyboard. For newer desktop Macs using keyboards without power buttons, the keyboard shortcut of control-eject will bring up this window.

Similar dialog windows can be called up by choosing Restart..., Shut Down..., or Log Out <user>... from the Apple menu. These only allow you to confirm and cancel your choice and show a context-specific restart/shut down/log out icon. Each of these windows also offer a two-minute countdown; once this countdown expires, the choice is automatically confirmed and carried out. The Log Out window can be called up with the keyboard shortcut command-shift-Q.