The staff members are the people who are tasked with various duties related to the site. :)
Admins generally handle the "back" end of the site, working on the site itself, such as its functionality and design, among other things. They often take on other duties (such as moderating, editing the guides, etc etc).
Admins have red names.
Mods handle disciplinary matters as well as ensuring that things are tidy and running smoothly. They patrol the forums (IC and OOC) to make sure no rule-breaking is taking place and to keep the peace. They are also kind of awesome.
There are three 'levels' of moderators, based on how long the person has been modding and how many privileges they can exercise (e.g. hard-deleting posts and suspending users from the site are two privileges only Level III mods have access to, while Level II and Level I mods can only 'soft-delete' (mask) posts, among other things.
Mods have blue names.
Archivists document in-character happenings and summarize them so that the general population of Caiuka can keep up with what is going on IC. They read many RPs and condense them into something easier to digest and release updates often via our IC News system.
Archivists have purple names.
Guide Writers help write the guides, be it by creating new ones or revising current ones.
Gs have light blue names.