This is a format for compact font storage in the OpenType system, allowing for the rasterization of text information. It differs from TrueType in its abilities to describe font symbols and with its font structure variation algorithm, depending on the change in size. CFF allows for increased screen clarity with high resolution, but this is not due to the font, but its rasterization.
BMP is format for storing bitmap images. In this format, you can only save bitmaps monolayer. For each pixel in different files may come different number of bits. The latest versions of the BMP has the ability to control color. In particular, you can specify the endpoints perform gamma correction and embed color profiles ICC.