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 Polo Boots:
Polo Boots are knee-high footwear that resemble horseback riding boots; they are usually made of leather, feature flat soles with low to medium heels, and may be worn to play polo or as a fashion statement.