shoulder pad

here is another link to a shoulder pad; measurements are given and the thickness of the pad is given:
http://www.hancockfabrics.com/product/iMainCat/4223/iSubCat/4231/iProductID/10197/10197.html
This pad is a (I cite from the page above)
Sew Perfect 3/4 Inch Lace Covered Drop Style Shoul
http://www.hancockfabrics.com/shopping/product/detailmain.jsp?itemID=7660&itemType=PRODUCT&iMainCat=4223&iSubCat=4231&iProductID=7660&itemType=PRODUCT
the page above links to another drop shoulder pad;
i wonder what shape this pad produces..does a drop pad mean that the pad 'drops' or 'falls' over the shoulder line..
What is the aim of a shoulder pad...i know that when drafting for a shoulder pad..the shoulder line is raised as well as the crown of the sleeve..but the crown seems to be raised because the armhole is now bigger...thus this pad is just made for the shoulder line...but what is a dropped shoulder pad....
note that this pad below
http://www.hancockfabrics.com/shopping/product/detailmain.jsp?itemID=7660&itemType=PRODUCT&iMainCat=4223&iSubCat=4231&iProductID=7660&itemType=PRODUCT
..it is made of a no-foam material specially from Sew Perfect and it is also fully covered in taffeta