82 Part I • Information Technology
images, photographs, sound bytes, and full motion video
can be displayed on the user’s screen as part of the docu-
ment. All this material is delivered to the user’s computer
via the Internet. The World Wide Web is the second “killer
app” of the Internet, and it has accelerated the already
rapid telecommunications revolution.
To use the World Wide Web, the user’s machine
must have a Web browser program installed. This software
package permits the machine to access a Web server, using
a dial-up telephone connection (with a modem), a broad-
band connection via DSL or cable, or a connection through
a LAN. As noted in Chapter 2, the most popular browser is
Microsoft’s Internet Explorer. When a user first logs into
the Web, she is connected to a “home” server at her ISP or
her own organization. She can then surf the Web by
clicking on hypertext links, or if she knows the address of
the site she wishes to visit—this address is called the
Universal Resource Locator(URL)—she can enter the
address directly into her browser. Alternatively, she can
search for a particular topic using a search engine
program such as Google, Microsoft Bing, Yahoo! Search,
or AOL Search. For Web site addresses, or URLs, she
expects to visit frequently, she can save the address as a
“bookmark” in her browser so that all she must do is click
on the appropriate bookmark to return to the Web site.
In the early days of the Web (say, 1992–1995), a
great deal of factual information was on the Web but very
little of commercial interest. Today, however, all major
organizations, and many lesser ones, have a significant
presence on the Web. The Web gives businesses a new way
to provide information about their products and services,
to advertise, and to communicate with customers and
suppliers and potential customers and suppliers. With
increasing frequency, the Web is being used to complete
sales, particularly of products, such as software, that can
be delivered via the Internet and of products such as books,
CDs, and clothes that can be delivered via regular mail or a
parcel service. (We will talk more about electronic com-
merce via the Web in Chapter 7.) Designing appealing
Web pages has become an art—organizations want to
make sure that their pages convey the right image. Check
out the home pages of some leading firms in any industry!
The Web has brought forth newer variations of
discussion groups and communication tools, including
blogs, wikis, and a variety of social networking applica-
tions. A blog(derived from Web log) is a user-generated
Web site where entries are made in journal style, typical-
ly displayed in reverse chronological order. Blogs can
deal with any subject—sometimes they serve as personal
online diaries, and sometimes they provide commentary
on a particular subject such as the environment, politics,
or local news. Typically blogs include text, images, and
links to other Web sites; sometimes blogs permit readers
to leave comments in an interactive format. A wikiis a
Web site that allows visitors to add, remove, or modify
the content of the Web site, often without the need for
registration. Thus a wiki becomes an effective tool for
mass collaborative authoring. A great example of a wiki
is Wikipedia, the free online encyclopedia found at http://www.
wikipedia.org.Social networking applications, which
have really caught on in the twenty-first century, include
the very popular Facebook, MySpace, and Classmates
and the more business-oriented LinkedIn and Plaxo—these
applications all permit users to post information about
themselves and to view information posted by others.
Another popular social networking application is
Twitter, which is a microblogging (i.e., short blogs)
service that enables its users to send and read messages
known as tweets.Tweets are text-only messages of up to
140 characters that are posted on the author’s Twitter
page and delivered to the author’s subscribers, who are
known as followers. Taken as a group, these newer varia-
tions of discussion groups and communication tools are
sometimes referred to as Web 2.0, a phrase which refers
to a perceived second generation of Web-based services
that emphasize online collaboration and sharing among
users.Accessing the Internet. How does an individual user
access the Internet? In the workplace, most users are
connected to a LAN, which in turn is connected to the
organizational backbone network, and then to the Internet.
From home or a small office, there are several alternatives.
Until 15 years ago, connections were almost always made
from a dial-in modem operating at speeds up to 56 kbps.
Today, however, an increasing number of users are
employing one of five newer, higher-speed alternatives:
Digital Subscriber Line(DSL), a cable modemconnec-
tion, a satelliteconnection,wirelessto the home, and fiber
to the home. Taken together, these five alternatives are
referred to as broadbandconnections.
DSL is a service offered by telephone companies
using the copper wires already installed in homes and
offices; it uses a sophisticated modulation scheme to move
data over the wires without interfering with voice traffic—
that is, both a voice conversation and an Internet hookup
can be active at the same time over a single DSL line. DSL
is sometimes called a “last mile” technology in that it is
used only for connections from a telephone switching
station to a home or office, not for connections between
switching stations. Data transfer rates on DSL are very
fast, varying from 256 kbps to 20 mbps when downloading
from the Internet to the home or office machine and from
256 kbps to 896 kbps when uploading from the home or