There are usually 3 types of finishing formats that your labels will be presented in: Roll, Fanfold or Sheet.
Roll
These labels are simply spooled or wound on a core.
Sheet
These are individual single sheet labels that are stacked together and packed in boxes.
Fanfold
Fanfold labels are die-cut with a perforation across the liner, and are folded back and forth along these perforations creating a stack of labels.