The term "high fashion" is typically used as a way of describing fashions that are trend-setting, unique, and exclusive. While mass market clothing is, er, mass-produced and easily accessed (and typically made with cheaper materials), high fashion products are defined in part by their quality materials and high cost. So in other words, when you see five people at the mall wearing the same taupe pea coat as you (isn’t that the worst?), it was probably made very quickly in a factory, and thus, doesn’t fall under the high fashion umbrella. On the other hand, if you get a custom wedding dress made by Vera Wang, or fill your closet with vintage finds, or spend (too much) money at small, one-of-a-kind boutiques, those things would generally be considered high fashion.