Page 104 - Electronic Commerce

Technology Infrastructure: The Internet and the World Wide Web

the ICANNWatch Web site). In 2011, ICANN decided to stop managing the addition of
new gTLDs so tightly. Since 2012, individuals and businesses have been able to petition
for just about any TLD they would like to have. This has generated some controversy; 79
you can learn more about the related issues on the Web sites of the Internet Governance
Project and the Center for Convergence and Emerging Networking Technologies,bothat
Syracuse University. Increases in the number of TLDs can make it more difficult for
companies to protect their corporate and product brand names, as you will learn in
Chapter 7.

MARKUP L ANGUAGES AND T HE WEB
Web pages can include many elements, such as graphics, photographs, sound clips, and
even small programs that run in the Web browser. Each of these elements is stored on the
Web server as a separate file. The most important parts of a Web page, however, are the
structure of the page and the text that makes up the main part of the page. The page
structure and text are stored in a text file that is formatted, or marked up, using a text
markup language. A text markup language specifies a set of tags that are inserted into the
text. These markup tags,or tags, provide formatting instructions that Web client software
can understand. The Web client software uses those instructions as it renders the text and
page elements contained in the other files into the Web page that appears on the screen of
the client computer.
The markup language most commonly used on the Web is HTML, which is a
subset of a much older and far more complex text markup language called
Standard Generalized Markup Language (SGML).Figure2-5,onthe next page,shows
how HTML, XML, and XHTML have descended from the original SGML specification.
SGML was used for many years by the publishing industry to create documents that
needed to be printed in various formats and that were revised frequently. In addition to
its role as a markup language, SGML is a metalanguage, which is a language that can be
used to define other languages. Another markup language that was derived from SGML
for use on the Web is Extensible Markup Language (XML), which is increasingly used
to mark up information that companies share with each other over the Internet. The X
in XML comes from the word extensible; you might see the word extensible shown as
eXtensible. XML is also a meta language because users can create their own markup
elements that extend the usefulness of XML (which is why it is called an “extensible”
language).

Copyright 2015 Cengage Learning. All Rights Reserved. May not be copied, scanned, or duplicated, in whole or in part. Due to electronic rights, some third party content may be suppressed from the eBook and/or eChapter(s).
Editorial review has deemed that any suppressed content does not materially affect the overall learning experience. Cengage Learning reserves the right to remove additional content at any time if subsequent rights restrictions require it.