Chauvinism means the belief that your country is superior to all others. If you traveled to China and complained about everything that was unfamiliar and talked about how much better things are back home, you'd be guilty of chauvinism.
While the main meaning of chauvinism is an exaggerated sense of patriotism, or being convinced that your country is vastly better than any other, the word is most familiar in the sense of male chauvinism. When it's used this way, it means a belief that men are better than women. The word comes from a Napoleonic soldier, Nicholas Chauvin, who was famous for his extreme patriotism — in other words, his chauvinism.