A heel is the bottom, back part of a shoe or boot that provides elevation. The styling and construction of a heel may vary (i.e., stacked, stilletto, spiked, sculptured, kitten).
About Leather Sandals:
Leather sandals are sandals, open-toed footwear with adjustable or fixed straps over the instep and ankle, that are made out of leather.
About Nubuck:
This is a grain leather that has been slightly brushed on the surface to create a very fine velvet-like appearance. The texture of nubuck is finer than suede.