Two kinds.
One is a large printer that exposes a digital image onto traditional photographic paper. Within this category there are two sub categories: Laser printers and LED printers. Laser printers primarily include the Durst Lambda and the Oce Lightjet. The Chromira is an LED printer.
The other kind is large format inkjet, generally Epson but sometimes HP. Also referred to as Giclee. Best papers in the biz according to most are from Hahnemuhle. A top pick among fine art photographers is their museum rag.