6850 is the rebuilds of the original bodies into a 6850 version for use in Outfit Studio.
There are both Nif Files and Object Files for each shape...
9477 is the rebuilds of the original bodies inot a 9477 version (aka UN7B) for use in Outfit Studio.
Again there are both Nif files and Object Files for each shape...
Originals is exactly what it is named... each original body reweighted in Outfit Studio so I could run them thru the clothing converter toolset.
Lattice is the lattice files to create the 6850 vertices versions. From what I understand these can be used in Blender as a morph of some kind...