This format is used for storing bitmap images in an Adobe Photoshop project file. It is stored in uncompressed form, and it includes color spaces, layers with masks, two-color settings, layer structures and other data that allow bitmap photos to be finely edited.
The artist is working in CMYK in Photoshop, on the theory that it's better to convert CMYK to RGB than vice versa, and we'll need both. We'd like to generate a master PDF file for each page which can be rendered into a suitable image for the web and can be used for a print run. That is, rather than export multiple versions from Photoshop, we'dySrZJo2.