Internet is a computer-based worldwide information network. The Internet is composed of a large number of smaller interconnected networks called internets. These internets may connect tens, hundreds, or thousands of computers, enabling them to share information with each other and to share various resources, such as powerful supercomputers and databases of information. The Internet has made it possible for people all over the world to effectively and inexpensively communicate with each other. Unlike traditional broadcasting media, such as radio and television, the Internet is a decentralized system. Each connected individual can communicate with anyone else on the Internet, can publish ideas, and can sell products with a minimum overhead cost. In the future, the Internet may have a dramatic impact on higher education and business as more universities offer courses and more companies offer goods and services online.
The internets from which the Internet is composed are usually public access networks, meaning that the resources of the network can be shared with anyone logging on to, or accessing, the network. Other types of internets, called intranets, are closed to public use. Intranets are the most common type of computer network used in companies and organizations where it is important to restrict access to the information contained on the network.
During the 1990s the Internet has grown tremendously in the number of people using it and the amount of information contained on it. According to the Internet Society, a non-profit society that studies and promotes the use of the Internet, 134 countries had full Internet connection and an additional 52 countries had limited access (for example, e-mail only) in 1996. A survey performed by the Internet consulting company Nua, found that approximately 45 million people were using the Internet at the end of 1996, with 30 million users in North America, 9 million users in Europe, and 6 million users in Asia and the Pacific.
Individuals, companies, and institutions use the Internet in many ways. Businesses use the Internet to provide access to complex databases, such as financial databases. Companies can carry out commerce online, including advertising, selling, buying, distributing products, and providing after-sales services. Businesses and institutions can use the Internet for voice and video conferencing and other forms of communication that allow people to telecommute, or work from a distance. The use of electronic mail (e-mail) over the Internet has greatly speeded communication between companies, among coworkers, and between other individuals. Media and entertainment companies use the Internet to broadcast audio and video, including live radio and television programs; to offer online chat, in which people carry on discussions using written text; and to offer online news and weather programs. Scientists and scholars use the Internet to communicate with colleagues, to perform research, to distribute lecture notes and course materials to students, and to publish papers and articles. Individuals use the Internet for communication, entertainment, finding information, and to buy and sell goods and services.