High culture is related to things in a given culture that are held in high esteem,like art, poetry,philosophy,religion(depending on culture) and are usually associated with refined educated people. The elite. Low culture usually refers to things associated with the masses,gossip magazines,Jerry Springer,talk back radio etc and is usually consumed by those on the poorer side.

In essence they are terms used by pompous bottom feeders that think you can split the world into the haves and the have nots without having regard to personal taste. There are plenty of millionaires that love gossip magazines drinking a 6 pack watching Jerry Springer on the telly as there are people who live in a cardboard boxes that spout Shakespeare can paint like Monet and play the piano.