The name "Wahi-Samskra" roughly translates as "The One Truth." Locals regard this realm as the one true world, of which all others are merely pale reflections. They know of the so-called core, certainly, and they're willing to trade with strangers (if you can offer them a good enough deal), but they don't really care. What happens beyond the borders of their world is of clearly lesser importance.
The realm is brutally civilized, with a strict caste system from Rajahs and Sultans and Water Lords down to lowest of peasants. Only three castes are officially outside the system:
Wasir, a term used for sparks (though many sparks from prestigious families also maintain a variety of noble or royal titles). Generally regarded as wise, if slightly crazy.
Djinn, a term used for monsters - most notably the creations of the mad Wasir Izn-Ab-JezQued, though it can also be applied to a wide variety of more domesticated creations. It's also generally reserved for beings that show at least near human intellect.
Haakta, or walking dead, or soulless. This term is used for outsiders, exiles, sand-raiders, and the like. The line between Haakta and Djinn is sometimes a bit blurry - both are considered to not be people per se; there are also several examples of individuals who are both Haakta and Wasir - most famous, of course, is Izn-Ab-JezQued. Note that this term does not apply to those who merely travel outside the cities - only those whose actual home is in the lifedraining desert or the un-real far realms.
The cities of Wahi-Samskra are each built around a major water supply - usually a well drilled down to the heart of the world, though a few cities have more exotic sources, and several major cities fight a fierce and perpetual war over territory along the great lifeblood river. Their walls contain lush fields, and farms, and mansions and palaces and hovels. Inter-city warfare is strictly ritualized; nothing is allowed that would damage the precious water supplies, and even sworn enemies are, ideally, supposed to cooperate against sand raiders or attacking djinn.
Outside the walls (and outside the area immediately adjacent to the lifeblood river), there is only sand, disrupted primarily by the occasional trade caravan or war party. Or, at least, that's the opinion of the city dwellers. As with most deserts, there's actually a remarkable variety of life if you really look for it - even if it's a rather harsh terrain for humans to live in.