The term "retro era" usually refers to the period in cultural history that has a nostalgic appreciation for past eras, particularly the 1950s, 1960s, and 1970s. However, the time span of what constitutes the retro era can vary depending on context, geographic regions, and personal perspectives. The retro movement or trend emerged in response to cultural changes, trends, fashion cycles, societal influences, entertainment industry trends, and people's nostalgia for an iconic past era with particular styles, aesthetics, art, design, fashion, technology, media, and even attitudes that resonate with present audiences. So, the start and end dates of the retro era remain inexact and subject to multiple interpretations, but it generally started gaining ground in the late 1990s.