From The Art and Popular Culture Encyclopedia
Internet pornography is pornography that is distributed by means of various sectors of the Internet, primarily via websites, peer-to-peer file sharing, or Usenet newsgroups. While pornography had been traded over the Internet since the 1980s, it was the invention of the World Wide Web in 1991 as well as the opening of the Internet to the general public around the same time that led to an explosion in online pornography.
Like videotapes and DVDs, the Internet has proved popular for distributing pornography because it allows people to view pornography more or less anonymously in the comfort and privacy of their homes. It also allows access to pornography by people whose access is otherwise restricted for legal or social reasons.