retro fashion can be thought of as bringing the iconic styles of the past back to life with today's production technology. the difference from vintage is that the garment isn't old, it's new in an old style. it describes new clothes that capture the spirit of a particular era (usually 20 to 50 years ago).
nostalgia, and i've stopped to talk about its psychological effects on people in my entries before, forms an emotional bond that makes people feel safe. fed by a longing for the aesthetic values of the past, this trend is the greatest proof of the fact that fashion is "a cycle that repeats itself." these days the retro elements combined with modern pieces (like a crop top over a pair of high-waisted retro pants) are thought to create a balanced style that blends the past with the future.
every decade has its own particular retro influence. for example, the 50s' poofy skirts and polka dots, the 60s' mini dresses and geometric patterns, or the 70s' bell-bottoms...