More than a quarter century ago the painter Ad Reinhardt declared that his new black-on-black canvases were the "last pictures which anyone can make." The critics raved, and many agreed with the "Black Monk" that his masterpieces would be history's "ultimate" paintings. Unfortunately, other artists refused to hand in their brushes, so art continued. Ever since, modern art has resembled a doomsday cult on the day after the deadline for the end of the world. The true believers awoke one day to find that the sun had risen, the mad prophet had disappeared, and they all had to find something to do with the rest of their lives.
This predicament is now called Postmodernism, and if you're confused about it, that's probably because you're beginning to understand it. If you're an artist, what follows will be old hat. But as a service to the layman I can define a few of the basic terms.