I think they meant to say "anti-pill". Fleece has a tendency to "pill" after washings. "Pilling" is when little blobs of fiber appear all over the surface. You can see this pilling problem on many types of sweaters -- especially wool sweaters. Anti-pilling fleece would be more resistant to this problem than regular fleece.
Whether regular or anti-pilling, I found out the hard way that there is a good way to wash and dry fleece and a bad way.
The good way is to wash and/or dry fleece only with fleece, and not with any other types of fiber. If it is clothing, turn the fleece garments inside out before washing. If you follow these rules, you will probably never experience pilling of your fleece.
The bad way to wash or dry fleece is to mix it with other types of fabric, especially if there is no way to turn the fleece inside-out (as in garments). The rubbing of the other types of fabric against the fleece will cause pilling.
How did I figure this out? I once washed and dried an entire load of fleece fabric I had just purchased. It came out beautifully. I then sewed it all into garments. As soon as they were washed in a regular load of laundry with other fabrics, the fleece pilled terribly. Lesson learned. It was the rubbing against other types of fabrics (regular woven fabrics seem especially bad) that made the fibers "pill".