The content of the Internet includes hypertext and multimedia. People put things on the Internet in a variety of data formats--as text, images, sound, movies, or interactive applications. Using hypertext to bind all this media together produces hypermedia. Typically, you'll use a World Wide Web client, or browser, to view this hypermedia.
As far as the meaning of the content that is on the Internet, that is harder to fully characterize. For that, you need to explore the Internet and decide for yourself.