Evolution of Internet

The Internet has its roots in a networking project started by the Pentagon's Advanced Research Projects Agency (ARPA), an agency of the U.S Department of Defense. ARPA's goal was to build a network that (1) allowed scientists at different physical locations to share information and work together on military and scientific projects and (2) could function even if part of the network were disabled or destroyed by a disaster such as a nuclear attack. That network, called ARPANET, became functional in September 1969, linking scientific and academic researchers across the United States.

 The original ARPANET consisted of four main computers, one each located at the University of California at Los Angeles, the University of California at Santa Barbara, the Stanford Research Institute, and the University of Utah. Each of these computers served as a host on the network. A host, more commonly known today as a server, is any computer that provides services and connections to other computers on the network. Hosts often use high-speed communications to transfer data and messages over a network.

 As researchers and others realized the great benefit of using ARPANET to share data and information, ARPANET underwent phenomenal growth. By 1984, ARPANET had more than 1,000 individual computers linked as hosts. Today, more than 550 million hosts connect to the Internet.

 Some organizations connected entire networks to ARPANET to take advantage of its high-speed communications. In 1986, the National Science Foundation (NSF) connected its huge network of five supercomputer centers, called NSFnet, to ARPANET. This configuration of complex networks and hosts became known as the Internet.

 Until 1995, NSFnet handled the bulk of the communications activity, or traffic, on the Internet. In  1995, NFSnet terminated its network on the Internet and resumed its status as a research network.

 Today, the Internet consists of many local, regional, national, and international networks. Numerous corporations, commercial firms, and other companies such as IBM provide networks to handle Internet traffic. Both public and private organizations own networks on the Internet. These networks, along with telephone companies such as Verizon and AT&T, cable and satellite companies, and the government, all contribute toward the internal structure of the Internet.

 Each organization on the Internet is responsible only for maintaining its own network. No single person, company, institution, or government agency controls or owns the Internet. The World Wide Web Consortium (W3C), however, oversees research and sets standards and guidelines for many areas of the Internet. The mission of the W3C is to contribute to the growth of the Web. More than 350 organizations from around the world are members of the W3C, advising, defining standards, and addressing other issues.

Internet2

 Internet2 is a not-for-profit research and development project that connects more than 200 universities and 115 companies via a high-speed private network. Founded in 1996, the goal of Internet2 is to develop and test advanced network technologies that will benefit Internet users in the short-term future. These technologies require an extremely high-speed network that exceeds the capabilities of today's Internet and networks. Examples of previous Internet2 projects that are now mainstream include telemedicine, digital libraries (online books, magazines, music, movies, speeches, etc.), and faster Internet services. Current Internet2 projects include interactive high-definition video and enhanced detection and resolution of network problems.

Connecting to the Internet

 Many home and small business users connect to the Internet via high-speed broadband Internet service. With broadband Internet service, your computer or mobile device usually is connected to the Internet the entire time it is powered on. Examples of broadband Internet service include cable, DSL, fiber, radio signals, and satellite.

• Cable Internet service provides high-speed Internet access through the cable television network via a cable modem.
• DSL (digital subscriber line) provides high-speed Internet connections using regular copper telephone lines.
• Fiber to the Premises (FTTP) uses fiber-optic cable to provide high-(speed Internet access to home and business users.
• Fixed wireless provides high-speed Internet connections using a dish-shaped antenna on your house or business to communicate with a tower location via radio signals.
• A cellular radio network offers high-speed Internet connections to devices with built-in compatible technology or computers with wireless modems.
• A Wi-Fi (wireless fidelity) network uses radio signals to provide high-speed Internet connections to compatible or properly equipped wireless computers and devices.
• Satellite Internet service provides high-speed Internet connections via a satellite dish that communicates with a satellite modem.

 Employees and students typically connect their computers to the Internet through a business or school network. The business or school network connects to a high-speed broadband Internet service.

 Many home users set up a Wi-Fi network, which sends signals to a communications device that is connected to a high-speed Internet service such as cable or DSL. Instead of using broadband Internet service, however, some home users connect to the Internet via dial-up access, which is a slower-speed technology. Dial-up access takes place when the modem in your computer connects to the Internet via a standard telephone line that transmits data and information using an analog (continuous wave pattern) signal. Users may opt for dial-up access because of its lower price or because broadband access is not available in their area.

 Mobile users access the Internet using a variety of Internet services. Most hotels and airports provide wired or wireless Internet services, such as Wi-Fi networks, allow mobile users to connect easily to the Internet with notebook computers, smart phones, and other mobile devices while away from a telephone, cable, or other wired connection. Many public locations, such as airports, hotels, schools, shopping malls, and coffee shops, are hot spots that provide Wi-Fi Internet connections to users with mobile computers or devices. At public locations, you may be required to agree to terms of service, obtain a password (for example, from the hotel's front desk), or perform some other action in order to connect to the Internet. Some cities provide free Wi-Fi Internet connections to all residents.

Access Providers

 An access provider is a business that provides individuals and organizations access to the Internet free or for a fee. For example, some Wi-Fi network provide free access while others charge a per use fee. Other access providers often charge a fixed amount for an Internet connection, offering faster speeds or more services for higher rates. Many Internet access providers offer services such as news, weather, financial data, games, travel guides, e-mail, photo communities, and online storage to hold digital photos and other files.

 Access providers are categorized as regional or national ISPs, online service providers, and wireless Internet service providers.

 An ISP (Internet service provider) is a regional or national access provider. A regional ISP usually provides Internet access to a specific geographic area. A national ISP is a business that provides Internet access in cities and towns nationwide. For dial-up access, some national ISPs provide both local and tool-free telephone numbers. Due to their larger size, national ISPs usually offer more services and have a larger technical support staff than regional ISPs. Examples of national ISPs are AT&T and EarthLink.

In addition to providing Internet access, an online service provider (OSP) also has many members-only features such as instant messaging or their own customized version of a Web browser. The more popular OSPs are AOL (America Online) and MSN (Microsoft Network). AOL  differs from many OSPs in that it provides gateway functionality to the Internet services to which members have access. AOL also provides free access to its services to any user with a broadband Internet connection.

 When selecting an ISP or OSP for dial-up access, ensure it provides at least one local telephone number. Otherwise, long-distance telephone charges will apply for the time you connect to the Internet.

 A wireless Internet service provider, sometimes called a wireless data provider, is a company that provides wireless Internet access to desktop and notebook computers and mobile devices, such as smart phones and portable media players, with built-in wireless capability (such as Wi-Fi) or to computers using wireless modems or wireless access devices. Wireless modem, which usually are in the form of a USB flash drive or a card that inserts in a slot in a computer or mobile device, generally dial a telephone number to establish a connection with the wireless Internet service provider. An antenna on or built into the computer or device, wireless modem, or wireless access device typically sends signals through the airwaves to communicate with a wireless Internet service provider. Some examples of wireless Internet service providers include AT&T, Boingo Wireless, Sprint Broadband Direct, T-Mobile, and Verizon Wireless.

How Data and Information Travel the Internet

 Computers connected to the Internet work together to transfer data and information around the world using servers and clients and various wired and wireless transmission media. On the Internet, your computer is a client that can access data, information, and services on a variety of servers.

 The inner structure of the Internet works much like a transportation system. Just as interstate highways connect major cities and carry the bulk of the automotive traffic across the country, several main transmission media carry the heaviest amount of traffic on the Internet. These major carriers of network traffic are known collectively as the Internet backbone.

 In the United States, the transmission media that make up the Internet backbone exchange data and information at several different major cities across the country. That is, they transfer data and data and information from one network to another until reaching the final destination.

Internet Address

 The Internet relies on an addressing system much like the postal service o send data and information to a computer at a specific destination. An IP Address, short for Internet Protocol address, is number that uniquely identifies each computer or device connected to the Internet.
 The IP address usually consists of four groups of numbers, each separated by a period. The number in each group is between 0 and 255. For example, the numbers 72.14.207.99 are an IP address. In general, the first portion of each IP address identifies the network and the last portion identifies the specific computer.

 These all-numeric IP addresses are difficult to remember and use. Thus, the Internet supports the use of a text name that represents one or more IP addresses. A domain name is the text version of an IP address. As with an IP address, the components of a domain name are separated by periods.

 The text in the domain name up to the first period identifies the type of Internet server.

 Every domain name contains a top-level domain (TLD), which is the last section of the domain name. A generic TLD (gTLD), such as the com, identifies the type of organization associated with the domain. The Internet server and gTLD portions of a domain name often are not required.

 The organization that assigns and controls top-level domains is the Internet Corporation for Assigned Names and Numbers (ICANN). For TLDs such as biz, com, info, name, net, and org, you register for a domain name from a registrar, which is an organization that sells and manages domain names.

For international Web sites outside the United States, the domain name also includes a country cod TLD (ccTLD), which is a two-letter country code, such as au for Australia. For example, www.philips.com.au is the domain name for Philips Autralia. Some smaller countries have granted use of their ccTLDs for commercial purposes such as tv (Tuvalu) for the television/entertainment industry.

 The domain name system (DNS) is the method that the Internet uses to store domain names and their corresponding IP addresses. When you specify a domain name, a DNS server translates the domain name to its associated IP address so that data and information can be routed to the correct computer. A DNS server is an Internet server that usually is associated with an Internet access provider.

 The growth of the Internet has led to a shortage of IP addresses. Thus, a new IP addressing scheme, called IPv6, may increase the number of available IP addresses.

The Internet

One of the major reasons business, home, and other users purchase computers is for Internet access. The Internet is a widely used research tool, providing society with access to global information and instant communications.

Further, access to the Internet can occur anytime from a computer anywhere: at home, at work, at school, in a restaurant, on an airplane, and at a park.

 The Internet, also called the Net, is a world-wide collection of networks that links millions of businesses, government agencies, educational institutions, and individuals. Each of the networks on the Internet provides resources that add to the abundance of goods, services, and information accessible via the Internet.

 Today, more than one billion home and business users around the world access a variety of services on the Internet. The World Wide Web, or simply the Web, and e-mail are two of the more widely used Internet services. Other services include chat rooms, instant messaging, and VoIP (Voice over Internet Protocol).

Computer Applications in Society

The computer has changed society today as much as the industrial revolution changed society in the eighteenth and nineteenth centuries.

 People interact directly with computers in fields such as education, finance, government, health care, science, publishing, travel, and manufacturing. In addition, they can reap the benefits from breakthroughs and advances in these fields. The following lines describe how computers have made a difference in people's interactions with these disciplines.

Education

 Education is the process of acquiring knowledge. In the traditional model, people learn from other people such as parents, teachers, and employers. Many forms of printed material such as books and manuals are used as learning tools. Today, educators also are turning to computers to assist with education.

 Many schools and companies equip labs and classrooms with computers. Some schools require students to have a mobile computer or mobile device to access the school's network or Internet wirelessly. To promote education by computer, many vendors offer substantial student discounts on software.

 Sometimes, the delivery of education occurs at one place while the learning occurs at other locations. For example, students can take a class on the Web. Some classes are blended; that is, part of the learning occurs in a classroom and the other part occurs on the Web. More than 70 percent of colleges offer distance learning classes. A few even offer entire degrees online.

Finance

 Many people and companies use computers to help manage their finances. Some use finance software to balance checkbooks, pays bills, track personal income and expenses, manage investments, and evaluate financial plan. This software usually includes a variety of online services. For example, computer users can track investments and do online banking. With online banking, users access account balances, pay bills, and copy monthly transactions from the bank's computer right into their personal computers.

 Many financial institutions' Web sites also offer online banking. When using a Web site instead of finance software on your computer, all your account information is stored on the bank's computer. The advantage is you can access your financial records from anywhere in the world.

 Investor often use online investing to buy and sell stocks and bonds – without using a broker. With online investing, the transaction fee for each trade usually is much less than when trading through a broker.

Government

 A government provides society with direction by making and administering policies. To provide citizens with up-to-date information, most government offices have Web sites. People in the United States access government Web sites to file taxes, apply for permits and licenses, pay parking tickets, buy stamps, report crimes, apply for financial aid, and renew vehicle registrations and driver's licenses. To provide these services, some Web sites require users provide personal information.

 Employees of government agencies use computers as part of their daily routine. North American 911 call centers use computers to dispatch call for fire, police, and medical assistance. Military and other agency officials use the U.S. Department of Homeland Security's network of information about domestic security threats to help protect against terrorist attacks. Law enforcement officers have online access to the FBI's National Crime Information Center (NCIC) through in-vehicle notebook computers, fingerprint readers and mobile devices. The NCIC contains more than 52 million missing persons and criminal records, including names, fingerprint, parole/probation records, mug shots, and other information.

Health Care

 Nearly every area of health care today uses computers. Whether you are visiting a family doctor for a regular checkup, having lab work or an outpatient test, or being rushed in for emergency surgery, the medical staff around you will be using computers for various purposes:

• Hospitals and doctors use computers and mobile devices to maintain and access patients records.
• Computers monitor patients' vital signs in hospital rooms and at home.
• Robots deliver medication to nurse stations in hospitals.
• Computers and computerized devices assist doctors, nurses, and technicians with medical tests.
• Doctors use the Web and medical software to assist with researching and diagnosing health conditions.
• Doctors use e-mail to correspond with patients.
• Pharmacists use computers to file insurance claims.
• Surgeons implant computerized devices, such as pacemakers, that allow patients to live longer.
• Surgeons use computer-controlled devices to provide them with greater precision during operations, such as for laser eye surgery and robot-assisted heart surgery.

 Many Web sites provide up-to-date medical, fitness, nutrition, or exercise information. These Web sites also maintain lists of doctors and dentist to help you find the one that suits your needs. They have chat rooms, so that you can talk to others diagnosed with similar conditions. Some Web sites even allow you to order prescriptions online.

 Two forms of long-distance health care are telemedicine and telesurgery. Through telemedicine, health-care professionals in separate locations conduct live conferences on the computer. For example, a doctor at one location can have a conference with a doctor at another location to discuss a bone X-ray. Live images of each doctor, along with the X-ray, are displayed on each doctor's computer.

 With telesurgery, also called remote surgery, a surgeon performs an operation on a patient who is not located in the same physical room as the surgeon. Telesurgery enables surgeons to direct robots to perform an operation via computers connected to a high-speed network.

Science

 All branches of science, from biology to astronomy to meteorology, use computers to assist them with collecting, analyzing, and modeling data. Scientists also use the Internet to communicate with colleagues around the world.

 Breakthroughs in surgery, medicine, and treatments often result from scientists' use of computers. Tiny computers now imitate functions of the central nervous system, retina of the eye, and cochlea of the ear. A cochlear implant allows a deaf person to listen. Electrodes implanted in the brain stop tremors associated with Parkinson's disease. Cameras small enough to swallow – sometimes called a camera pill – take pictures inside your body to detect polyps, cancer, and other abnormalities.

 A neural network is a system that attempts to imitate the behavior of the human brain. Scientists create neural networks by connecting thousands of processors together much like the neurons in the brain are connected. The capability of a personal computer to recognize spoken words is a direct result of scientific experimentation with neural networks.

Publishing

 Publishing is the process of making works available to the public. These works include books, magazines, newspapers, music, film, and video. Special software assists graphic designers in developing pages that include text, graphics, and photos; artists in composing and enhancing songs; filmmakers in creating and editing film; and journalists and mobile users in capturing and modifying video clips.

 Many publishers make their works available online. Some Web sites allow you to copy the work, such as a book or music, to your desktop computer, mobile computer, smart phone, or other mobile device.

Travel

 Whether traveling by car or airplane, your goal is to arrive safely at your destination. As you make the journey, you may interact with some of the latest technology.

 Vehicles manufactured today often include some type of onboard navigation system, such as Onstar. Many mobile devices such as smart phones have built-in navigation systems. Some mobile users prefer to carry specialized handheld navigation devices.

 In preparing for a trip, you may need to reserve a car, hotel, or flight. Many Web sites offer these services to the public. For example, you can order airline tickets on the Web. If you plan to drive somewhere and are unsure of the road to take to your destination, you can print direction s and a map from the Web.

Manufacturing

 Computer-aided manufacturing (CAM) refers to the use of computers to assist with manufacturing processes such as fabrication and assembly. Industries use CAM to reduce product development costs, shorten a product's time to market, and stay ahead of the competition.

 Often, robots carry out processes in a CAM environment. CAM is used by variety of industries, including oil drilling, power generation, food production, and automobile manufacturing. Automobile plants, for example, have an entire line of industrial robots that assemble a car.

 Special computers on the shop floor record actual labor, material, machine, and computer time used to manufacture a particular product. The computers process this data and automatically update inventory, production, payroll, and accounting records on the company's network.

Examples of Computer Usage

Every day, people around the world rely on different types of computers for a variety of applications. To illustrate the range of uses for computers, this section takes you on narrative tour of five categories of users:

• Home user
• Small office/home office (SOHO) user
• Mobile user
• Power user
• Enterprise user

Home User

 In an increasing number of homes, the computer no longer is a convenience. Instead, it is a basic necessity. Each family member, or home user, spends time on the computer for different reasons that include personal financial management, Web access, communications, and entertainment.

 On the Internet, home users access a huge amount of information, conduct research, take college classes, pay bills, manage investments, shop, listen to the radio, watch movies, read books, file taxes, book airline reservations, make telephone calls, and play games. They also communicate with others around the world through e-mail, blogs, instant messages, and chat rooms using personal computers, smart phones, and other mobile devices. Home users share ideas, interests, photos, music, and videos on social networking Web sites. With a digital camera, home users take photos and then send the electronic images to others. Using a Web cam, home users easily have live video calls with friends, family members, and others.

 Many home users have a portable media player, so that they can download music or podcast, and listen to the music and/or audio at a later time through earbuds attached to the player. They also usually have one or more game consoles to play video games individually or with friends and family members.

 Today's homes also typically have one or more desktop computers. Many home users network multiple desktop computers throughout the house, often wirelessly. These small networks allow family members to share an Internet connection and a printer.

 Home users have a variety of software. They type letters, homework assignments, and other documents with word processing software.

Personal finance software helps the home user with personal finances, investments, and family budgets. Other software assists with preparing taxes, keeping a household inventory, setting up maintenance schedules, and protecting home computers against threats and unauthorized intrusions.

 Reference software, such as encyclopedias, medical dictionaries, or a road atlas, provides valuable information for everyone in the family. With entertainment software, the home user can play games, compose music, research genealogy, or create greeting cards. Educational software helps adults learn to speak a foreign language and youngsters to read, write, count, and spell.

Small Office/Home Office User

 Computers assist small business and home office users in managing their resources effectively. A small office/home office (SOHO) includes any company with fewer than 50 employees, as well as the self-employed who work from home. Small offices include local law practices, accounting firms, travel agencies, and florists. SOHO users typically have a desktop computer to perform some or all of their duties. Many also have smart phones or other mobile devices to manage appointments and contact information.

SOHO users access the Internet – often wirelessly – to look up information such as addresses, directions, postal codes, flights and package shipping rates or to send and receive e-mail messages or make telephone calls.

 Many have entered the e-commerce arena and conduct business on the Web. Their Web sites advertise products and services and may provide a means for taking orders. Small business Web sites sometimes use a Web cam to show the world a live view of some aspect of their business.

 To save money on hardware and software, small offices often network their computers. For example, the small office connects one printer to a network for all employees to share.

 SOHO users often work with basic business software such as word processing and spreadsheet programs that assist with document preparation and finances. They are likely to use other industry-specific types of software. An auto parts store, for example, will have software that allows for looking up parts, taking orders and payments, and updating inventory.

Mobile User

 Today, business and schools are expanding to serve people across the country and around the world. Thus, increasingly more employees and students are mobile users, who work on a computer or mobile device while away from a main office, home office, or school. Examples of mobile users are sales representatives, real estate agents, insurance agents, meter readers, package delivery people, journalists, consultants, and students.

 Mobile users often have mobile computers and/or mobile devices. With these computers and devices, the mobile user connects to other computers on a network or the Internet, often wirelessly accessing services such as e-mail and the Web. Mobile users can transfer information between their mobile device and another computer, such as one at the main office or school. For entertainment, the mobile user plays video games on a handled game console and listens to music or watches movies on a portable media player.

 The mobile user works with basic business software such as word processing. With presentation software, the mobile user can create and deliver preparations to a large audience by connecting a mobile computer or device to a video projector that displays the preparation on a full screen. Many scaled-down programs are available for mobile devices such as smart phones.

Power User

 Another category of user, called a power user, requires the capabilities of a workstation or other type of powerful computer. Examples of power users include engineers, scientists, architects, desktop publisher, and graphic artists.

Power users often work with multimedia, combining text, graphics, audio and video into one application. These users need computers with extremely fast processors because of the nature of their work.

 The power user's workstation often contains industry-specific software; for example, engineers and architects use software to draft and design floor plans, mechanical assemblies, or vehicles. A desktop publisher uses software to prepare marketing literature. A graphic artist uses software to create sophisticated drawings. This software usually is expensive because of its specialized design.

 Power user exist in all types of businesses.

Some work at home. Their computers typically have network connections and Internet access.

Enterprise User

 An enterprise has hundreds or thousands of employees or customers that work in or do business with offices across a region, the country, or the world. Each employee or customer who uses a computer in the enterprise is an enterprise user.

 Many large companies use the words, enterprise computing, to refer to the huge network of computers that meets their diverse computing needs. The network facilitates communications among employees at all locations. Users access the network of servers or mainframes through desktop computers, mobile computers, and mobile devices.

 Enterprises use computers and the computer network to process high volumes of transactions in a single day. Although they may differ in size and in the products or services offered, all generally use computers for basic business activities. For example, they bill millions of customers, prepare payroll for thousands of employees, and manage thousands of items in inventory. Some enterprises use blogs to open communications among employees, customers and /or vendors.

 Enterprises typically have e-commerce Web sites, allowing customers and vendors to conduct business online. The Web site also showcases products, services, and other company information.

 The marketing department in an enterprise uses desktop publishing software to prepare marketing literature. The accounting department uses software fro accounts receivable, accounts payable, billing, general ledger, and payroll activities.

 The employees in the information technology (IT) department keep the computers and the network running. They determine when the company requires new hardware or software.

 Enterprise users work with word processing, spreadsheet, database, and presentation software. They also may use calendar programs to post their schedules on the network. And, they might use smart phones or mobile devices to maintain contact information. E-mail programs and Web browsers enable communications among employees, vendors, and customers.

 Many employees of enterprises telecommute. Telecommuting is a work arrangement in which employees work away from a company's standard workplace and often communicate with the office through the computer. Employees who telecommute have flexible work schedules so that they can combine work and personal responsibilities, such as child care.