The Internet has many uses. Electronic mail is an efficient and inexpensive way to send and receive messages and documents around the world within minutes. The World Wide Web is an important advertising medium and a channel for distributing software, documents, and information services. The Internet also has created hundreds of �virtual communities� made up of people who share an interest in a technical discipline, hobby, or political or social movement. Most individual users connect their computer�s modem to a telephone line and set up an account with an Internet Service Provider (ISP), which provides local or regional access to the Internet backbone. Many other users connect to the Internet through a school or business LAN.