Tags are similar to what you do with multiple hardware but rather than selecting every device manually you can use a tag, to include all the devices with this tag. For example you can use all server. With the field excluded hardware you can select devices, that you don't want to include, for example you want every desktops except one. You can also use tags for this, for example if you have a not reboot tag you can select all devices for a reboot but exclude all devices with this tag to make sure there is no reboot done there, or in this case you can select every desktop, but the ones with Windows 10 installed.
If you click on the tag or the eye icon, you can see to what devices the job is applied to.