And again @Hanna_Brassheart to the rescue.
Yeah, Hanna got everything spot on, the number next to the server name usually details the percentage of players playing out of the maximum capacity that server can handle (I believe).
@Jacoby_Elderfun1 If you have read comics or are familiar with the idea of the Multiverse this is basically the same concept, there is one common world but different versions of it. For our servers, it means they both exist at the same time and have the same world but people can't interact with each other between servers they would have to swap server.
So if you are on the more populated server and are dumping Aether into a Great Engine but nothing is happening, no matter how many times you put a full Aethermeter in it might be good to post here, see if we can get a lot of people doing it to see if there is an issue.