*.raw files........

G'day all,Im all my work for Fly! II I have always used *.bmp files as the working file and then converted to either *.pbm or *.pbg files as needed by Fly! II.My question is that sometimes I see that other people use *.raw files and I am wondering what is the advantage of using raw files???Any graphic guru's able to shed light as to why?Cheers,Roger