More than likely you've asked someone where they got a particular item of clothing that you liked and they responded that it was "vintage." For those of you who are not educated on clothing slang, "vintage" is the word used for clothing that comes from another time, another era.
Some people think anything past 25 years is a qualification for vintage clothing, while others opinions differ. Wearing vintage clothing is really a personal choice. If you are attracted to the clothing of a certain time period, then there is no shame in expressing it. Even clothing from your great grandmother or grandma is considered very "chic" these days.