All alarms are contained in alarm groups. Just like alarms, alarm groups have certain properties. The name is the only really important property.
Each alarm group has a name. Names can be anything.
The color of the alarm group. You need to have a color scheme selected for the color to be used in the main window.
Use the buttons to specify a template alarm. If you don't specify one, or choose to use the default, the template alarm from the settings will be used. The template alarm will be shown when you add a new alarm to this group. This may be handy if you have different kinds of alarm groups. For example, a birthday alarm group could have a template alarm which is already set to sound every year.
Type of alarm group
Here alarm groups can be set to be synchronized with some source, like Outlook appointments. This requires the appropriate plug-in to be available. If you don't specify anything here, you will just have a normal alarm group. Otherwise, the behaviour of the alarm group will depend on the selected plug-in (some plug-ins only support read-only alarm groups). Currently, the alarmgroups are all synchronized once every 30 minutes.