When it works, it REALLY works. There is no trash in the streets, it's all in these tubes that you place your trash in. Some buildings have these tubes integrated, some have the tubes in the street kind of variety. Every now and then you'll see special trucks come in that quite literally suck the garbage out of the ground to empty out the underground storage.
Sometimes it doesn't work though. Maybe it's because people fill up the tubes with weird shit but I think mostly it's just because they don't empty the system often enough. When I first moved in this was a big issue, but now I haven't seen it in a while (actually years probably) so maybe they've figured out the a schedule better.
It is really nice, it works well and truly is an out of sight out of mind kind of thing. I'd imagine it's easier for garbage collection too since it's centralized, you don't have trucks coming around to each house or block.
There is some garbage that doesn't go in the chutes. Electrical appliances, glass, larger items that won't fit such as pots and pans and lighter furniture. They all go in special garbage rooms so still off the streets, but not quite as cool as giant tubes underground.