What is a fashion classic?

 A fashion classic is a certain look, design, or fabric that stays in fashion for a long time. These looks usually adjust a bit, but remain distinct, for example the tuxedo. The buttons may change, and the shoulders may evolve, but the tuxedo remains. Articles like jeans, tee shirts, coats, and sweaters are all examples of classics.

Souce: (bonzle.com)