The public parts of this wiki describe setting information beyond what the rulebook has to offer. Some is written by staff, and some is written by players. The world does not have internet (or television, telephones, telegrams, etc.) — you can think of the information in the wiki as stuff you could learn, between events, by reading newspapers, almanacs, and other publications, and by keeping up with general world events.
More-or-less, the information in the wiki is "canon." Some of it could technically be hearsay or misinformation (or just be very niche), but it is broadly available and accepted in the game world: even in player-written sections of the wiki, content is moderated by staff, and you should not use the wiki as a personal journal or character publication.
Staff also moderates the wiki to make sure the Code of Conduct is followed. In particular, avoid cultural appropriation, ethnic caricatures, sexism or misogyny, racist or cryptoracist cultures, or anything written to harass people. The game world is explicitly intended to be diverse and welcoming, and the wiki should not violate that.
The continent of Ihlathi has hundreds of millions of people. There are many regions, cities, and towns, and each has many tangled cultures and subcultures. Neither staff nor the rulebook could enumerate them, nor would they try. The main player section of the wiki is where you (players or staff) can write the details you want to see in the world — you can grow the setting and give it life.
By writing this sort of material in the wiki, you allow other players to use it or build off it. Of course, they could write their own, and continue to expand the setting.
The second main section of the wiki describes some high-level current events of Ihlathi and its regions (etc.). It is written by staff, but visible to everyone.
Over time, this grows into a timeline of world events — some (but not all) of them directly related to, or caused by, PC decisions and actions in the game. It should also provide a sense of the passage of time, of recent history, and of how the world "works," especially outside of the confines of the game’s immediate setting and trappings.
The last main wiki section is staff-only — players shouldn't be able to see it; if you find yourself on a staff-only page when you shouldn't be, don't read it, and let staff know it happened.