It has ink reservoirs rather than cartridges, and small, permanently plumbed tubes that go from the reservoirs to the print head.
Not only does that mean there's no way it can tell what kind of ink I'm putting in it, it also means the tanks are fucking massive. It's so nice being able to go O(years) without refilling.
It cost about twice what a comparable, cartridge-based printer cost at the time. To this day I still consider it one of the best purchases I've ever made.