A Jelly Roll contains 40 strips, 2 1/2" x width of fabric (always 40, regardless of the number of pieces in the line, so you could have duplicates or have a few pieces of the line left out).   Honey Buns are 1.5" x width of fabric and are a perfect complement to the Jelly Roll.  Charm packs vary in the number of pieces but they are all 5" squares - sometimes call nickels.  Layer Cakes are 10" pieces.   All of these are great time savers and a wonderful way to explore a fabric line.