Connecting to the Internet
A computer alone is not enough to access the Internet. In addition to web browser soft-ware, the computer needs specific hardware and a connection to an Internet Service Provider to view web pages. This section describes the components that enable Internet access.
First, a computer must have a modem or network card. A modem is hardware that enables a computer to connect to a network via phone lines. A modem converts data to audio tones and transmits the data over phone lines. A network card, also called a network interface card (NIC), is hardware that allows a computer to connect to the Internet through a network or a high-speed Internet connection, such as a local area network (LAN), cable modem or Digital Subscriber Line (DSL).
After ensuring that a computer has a modem or a network card (most computers come with one or both of these), the next step is to register with an Internet Service Provider (ISP). Computers connect to an ISP using a modem and phone line, or via a NIC using a LAN, DSL or cable modem. The ISP connects computers to the Internet. Most college and university campuses offer network connections, and many communities now offer wireless access. If a network connection is not available, then popular commercial ISPs, such as AOL (www.aol.com), Comcast (www.comcast.net), Earthlink (www.earth-link.net), Verizon (www.verizon.com), Microsoft Network (www.msn.com) and NetZero (www.netzero.net) are alternatives.
Bandwidth and cost are two considerations when deciding which commercial ISP ser-vice to use. Bandwidth refers to the amount of data that can be transferred through a com-munications medium in a fixed amount of time. Different ISPs offer different types of high-speed connections, called broadband connections—which include DSL, cable modem and Integrated Services Digital Network (ISDN)—and slower dial-up connec-tions. Each connection type has a different bandwidth and cost to users.
Broadband is a category of high-bandwidth Internet service that is most often pro-vided to home users by cable television and telephone companies. DSL is a broadband ser-vice that allows computers to be connected at all times to the Internet over existing phone lines, without interfering with telephone services. DSL requires a special modem provided by the ISP. Like DSL, cable modems enable the computer to be connected to the Internet at all times. Cable modems transmit data over the cables that bring television to homes and businesses. Unlike DSL, the bandwidth is shared by many users. This sharing can reduce the bandwidth available to each person when many use the system simultaneously. ISDN provides Internet service over either digital or standard telephone lines. ISDN requires spe-cialized hardware, called a terminal adapter (TA), which is usually obtained from the ISP.
Dial-up service uses an existing telephone line. If a computer is connected to the Internet, the user usually cannot receive voice calls during this time. If the voice calls do connect, the Internet connection is interrupted. To prevent this, users may choose to install an extra phone line dedicated to Internet service.
Fiber optics are replacing traditional metal cables in many computer networks due to their greater bandwidth and mechanical advantages that provide a better signal. Though their popularity is currently limited by the high cost of materials and installation, consis-tent improvements in the industry will allow fiber optic cables to become a key element of the communications industry in the near future.
Once a computer is connected to a network, the user must choose a web browser for navigating the Internet. Internet Explorer is preinstalled on all Windows machines, and your version can be updated at www.microsoft.com/ie. Firefox can be downloaded at www.mozilla.com/firefox, and can be installed on many different operating systems. When installing this browser, select Custom when prompted for a setup type, and ensure that the DOM Inspector option is selected in the next screen. Doing so will ensure that you have additional Firefox functionality that we discuss in Chapter 12.
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