Under the Section Available Updates is a list of available updates, and which Device needs those Updates. Critical Updates are marked red.
By Clicking on the Number of Devices you can see which devices need the update, and selecting them bring you to an installation Wizard.
Additionally you can also select, wheter you want the device to reboot or not and when to reboot it.
Important: Some Updates require a reboot, so if you select no reboot, keep in mind that you might have to reboot your device to finish the installment of the update. Because of this, we recommend always updating with a reboot.