Classic clothing is a style that lasts over many seasons. Take the 90s, for example. It had recently made its comeback and many fashion designers are continually exploring the aesthetic of 90s, as of now.
Meanwhile, a fad is a style that only lasts for a season. Visors, silly bandz, and double-pop collars are all fads that become popular in their own respective time, but quickly disappeared. However, fads differ among people. Bellbottom pants could be out of season for someone, while it could be another's favourite type of clothing to wear on a daily basis.
