Hi Cheviot and welcome to fibreland. Um.....it's batts not butts
but I quite like the mistake
Batts are what comes off a drum carder so carded fleece presented a bit like a Santa Claus beard.
Tops is a similar preparation but comes from a commercial carding machine and is presented as a long fluffy endless strip.
Roving is a thinner preparation, for example pencil roving is about the thickness of a pencil and can be spun without further drawing - sounds a bit boring
I turn my tops and batts into rovings by hand before I spin them.
All of them have the fibres running roughly parallel to eachother for worstead spinning (batts rather less then the others), but can be turned into rolags for woollen spinning....or something
'Butt' is a fibre word, as well as the obvious US meaning, and means the end of a wool staple (bundle) which was closest to the animal before shearing. The other end is the tip.
There are so many fibre and spinning words to learn - it should keep you happy for ages