'tis SSD, not too big, c 200 divided into two logical drives. E and F are part of an old laptop drive and is were most of the storage is.
C is kept for the OS, but so many companies don't ask and plonk stuff on it. Most tedious. D was supposed to contain just Office and the like. Roughly the layout.
Another USB SSD sitting on top, but I've never got the hang of the Samsung auto backup. Just thought I'd mention that in passing.