I have to admit, I used to think embroidery (or cross stitch) floss and thread were the same thing. I thought floss was what those from the UK and Canadians (like myself) called it, and Americans called it thread (kinda like colour and color). After doing a little digging, I found out there actually is a difference.
Put simply, skeins are made up of 6 strands of THREAD, together all 6 strands make a skein of FLOSS.
All in all, it doesn't matter whether you call it floss or thread. Really, the two terms can be used interchangeably. I have been calling it floss for so long, that I probably always will!
What do you call it?