Information Jungle HomeLesson One HomePfau Library What is the Internet? Definition of a Computer Network A COMPUTER network, sometimes referred to simply as a "network," is composed of the computer equipment (hardware) and programs (software) that allow two or more computers to connect to each other so that files (documents, graphics, information, messages, software, etc.) may be shared among them.  A computer network also may allow for shared use of equipment such as a printer among several computers.  It requires a person with specialized knowledge to select the right equipment and programs, install everything correctly, and keep it running smoothly.  A small network might involve just a few computers in one building, or even one room, while a larger network might include all the computers on a university campus.  It is possible for a single computer to be part of more than one network. The Internet is a Network of Computer Networks Just as a network connects individual computers, the Internet connects individual networks.  However, not all networks are part of the Internet.  To connect a computer to the Internet requires subscribing to some form of Internet access. Companies that sell Internet access, also called Internet Service Providers (ISPs), allow your computer to become part of their network which is already connected to the Internet.  A Brief History IT ALL began in 1969 with the Advanced Research Projects Agency Network (ARPAnet) and the U.S. Department of Defense.  The D.O.D. invented a new type of computer network to ensure that if the Soviets attacked and succeeded in destroying some computers, the rest would still be able to connect to each other.  No single computer controlled the entire network. Instead, there were multiple control centers called "nodes."  If a node lost its connection to the network, the flow of communication would simply detour and take another route.  The D.O.D. also established a universal standard of computer communication called Internet Protocol (IP) that enabled all different kinds of computers to connect to each other efficiently and reliably. Other government agencies, commercial concerns, and universities that wanted to connect to ARPAnet copied the idea of a decentralized network, adopted the D.O.D.'s Internet Protocol standard, and began to build on these ideas.  People quickly discovered how useful a network of networks could be when electronic mail (e-mail) was invented and they went on to discover and develop other uses, a process which is still going on today. What Can You Do With the Internet? The Internet makes it possible for people to: Send and receive personal electronic messages (e-mail). Read and post public electronic messages to central locations where others may do the same (Usenet, newsgroups). Use resources on other computers no matter where the computers are physically located (Telnet). Send and receive documents, software, graphics, and other types of computer files (gopher, FTP, Web). Simultaneously (also called "real time") exchange messages (chat). View combined presentations of text, graphics, animations, sounds, etc., sent to their computer from another one upon request (Web). Distinctions among these functions are not always clear.  In many cases there are several ways of achieving the same task.  The Web, for example, now includes features that in the past were separate. The ability to send and receive e-mail does not automatically guarantee that you will be able to access the Web.  You need an Internet account that allows Web access and a browser.  A browser is a software program that enables your computer with an Internet account to get to the Web.  Internet Service Providers usually provide some sort of browser along with the accounts they sell.  Netscape and Internet Explorer are two of the best browsers.  Get further details from your e-mail provider. Who Owns the Internet? NO ONE owns the whole thing.  The various government agencies, universities, organizations, and businesses that contribute to it each own a portion, that is to say, the hardware and software that they paid for. Is the Internet Free? NO, IT'S definitely not!  If you want to access the Internet from your home computer, in addition to buying the appropriate hardware and software, you will need to subscribe to a commercial Internet service which will bill you.  If a university wants Internet access it must buy a much more hardware and software than an individual and a different type of Internet connection.  This can easily cost thousands and thousands of dollars.  As a student, professor, or staff member, you may be able to get to the Internet through a computer and Internet connection provided by the university which gives it the appearance of being free, but the university is paying for that access. Lesson One continues on the next page.