Batting - Batting is fiber that has been prepared into sheets of lofty fiber that is traditionally used for quilting. It resembles poly-fill that you see used for pillow stuffing . Batting is lofty and the individual fibers are messy (going in all directions.) These qualities make carded batts a fine choice for sculptural needle felting. Roving - This is the most commonly used term I hear to broadly describe all types of fiber for felting. Technically speaking, roving is fiber that has been prepared into long ropes be spun into yarn. (Or better yet for hair for needle felted projects. )
If you have only used roving for your needle felted projects, you will be AMAZED at the difference using quality wool batting will make.