The Cloud Network was introduced after the 1.6.4-2.0 update. The idea was to bring all servers together, making us closer, connecting the community. Minecraft servers are hard enough as is to advertise. Some people honestly hate advertisements. That's why we've introduced the cloud, so anyone that plays Aether II can find servers easily. These are community hosted servers, that aren't infiltrated by Gilded Games or the Aether Team. Anyone can make a "cloud" server. Most clouds on there are using Cauldron which allows them to have a Forge server with Bukkit functionality. You can toggle whether you want your cloud to be on the cloud network, you can name your cloud and even give it fancy colors, and you can have a description. While you are in multiplayer, you can even switch servers with the in-game "Cloud Network" tab.
When starting a server, Aether II will generate some properties in your server.properties, if not you can add them manually.
Toggleable. true or false. True will place your server on the cloud, false shall not.
This will set the name of your cloud, left blank will be defaulted to Aether II Server. If you want to do fancy colors in your cloud name, you can type \u00A7#. Replace # with 1-9 or a-f
Example: \u00A7e will make your name yellow.
Here's a list of Minecraft color codes http://minecraft.gamepedia.com/Formatting_codes
This will give your cloud a description. Descriptions can be found when you click on a cloud, under the message of the day.