If you mean the diff between Servent/Knight/Monarch, it's pretty simple.
King -> Admin + Tester
Lord -> Mod
Monarch -> Best non-staff duelists
Knights -> Normal duelists
Servents -> Beginning duelists
When you get your test (from one of the kings) you will be given the rank of either Servent, Knight, or Monarch. As soon as you can, contact either me or another king to be tested to be given your rank.