Fashion changes in time because of changes in societal norms and trends. Fashion is influenced in part by celebrities, and popular celebrities change as the decades change. Other fluid aspects of pop culture, like television shows and movies, also influence fashion.
As celebrities and pop culture icons adhere to different fashion trends introduced by innovative designers, society follows suit. Individuals love to imitate, creating dynamism in fashion. Trends in fashion also change based upon changes in levels of modesty. Western clothing has become less conservative in time. It has become increasingly socially acceptable to wear less. Hemlines in skirts have risen, and styles have become more casual overall.