vintage

I know what "vintage" is, and I know which clothes or accessories should be called as vintage and which should not be; but when a friend of mine ask me what vintage is, I didn't really know what should I say. I just said "errrm...., antique?".

I've also googled and I haven't really found anything useful.
so, does anybody know?

all images were taken from here. I heart them so much and I think you should too. :)