Information Technology Reference
In-Depth Information
SUMMARY
Principle
The Internet is like many other technologies—it pro-
vides a wide range of services, some of which are
effective and practical for use today, others that are
still evolving, and still others that will fade away from
lack of use.
browsers. A collection of pages on one particular topic,
accessed under one Web domain, is called a Web site.
Hypertext Markup Language (HTML) is the standard page
description language for Web pages. The HTML tags let the
browser know how to format the text: as a heading, as a list,
or as body text, for example. HTML also indicates where
images, sound, and other elements should be inserted. Some
newer Web standards are gaining in popularity, including
Extensible Markup Language (XML), Extensible Hypertext
Markup Language (XHTML), Cascading Style Sheets (CSS),
Dynamic HTML (DHMTL), and Wireless Markup Language
(WML).
Web 2.0 refers to the Web as a computing platform that
supports software applications and the sharing of information
between users. Over the past few years, the Web has been
changing from a one-directional resource where users find
information to a two-directional resource where users find
and share information. The Web has also grown in power to
support complete software applications and is becoming a
computing platform on its own. A rich Internet application
(RIA) is software that has the functionality and complexity of
traditional application software, but runs in a Web browser
and does not require local installation. Java is an object-
oriented programming language from Sun Microsystems
based on the C++ programming language, which allows small
programs, called applets, to be embedded within an HTML
document.
The Internet started with ARPANET, a project sponsored by
the U.S. Department of Defense (DoD). Today, the Internet is
the world's largest computer network. Actually, it is a collec-
tion of interconnected networks, all freely exchanging infor-
mation. The Internet transmits data from one computer
(called a host) to another. The set of conventions used to pass
packets from one host to another is known as the Internet
Protocol (IP). Many other protocols are used with IP. The best
known is the Transmission Control Protocol (TCP). TCP is so
widely used that many people refer to the Internet protocol as
TCP/IP, the combination of TCP and IP used by most Internet
applications. Each computer on the Internet has an assigned
address to identify it from other hosts, called its Uniform
Resource Locator (URL).
People can connect to the Internet in several ways: via a
LAN whose server is an Internet host, or via a dial-up con-
nection, high-speed service, or wireless service. An Internet
service provider is any company that provides access to the
Internet. To use this type of connection, you must have an
account with the service provider and software that allows a
direct link via TCP/IP.
Principle
Because use of the Internet and the World Wide Web
is becoming universal in the business environment,
management, service and speed, privacy, and secu-
rity issues must continually be addressed and
resolved.
Principle
Originally developed as a document-management
system, the World Wide Web is a hyperlink-based
system that is easy to use for personal and business
applications.
Internet and Web applications include Web browsers; e-mail;
career information and job searching; Telnet; FTP; Web logs
(blogs); podcasts; Usenet and newsgroups; chat rooms; Inter-
net phone; Internet video; content streaming; instant mes-
saging; shopping on the Web; Web auctions; music, radio, and
video; office on the Web; 3-D Internet sites; free software; and
other applications.
You use a search engine to find information on the Web by
specifying words that are key to a topic of interest, known as
keywords. Search engines scour the Web with bots (auto-
mated programs) called spiders that follow all Web links in
an attempt to catalog every Web page by topic.
You use e-mail to send messages. Various technologies
are available for accessing and managing e-mail including
online e-mail services, POP, and IMAP. The Internet also
offers a vast amount of career and job search information.
The Web is a collection of tens of millions of servers that work
together as one in an Internet service providing information
via hyperlink technology to billions of users worldwide.
Thanks to the high-speed Internet circuits connecting them
and hyperlink technology, users can jump between Web pages
and servers effortlessly—creating the illusion of using one big
computer. Because of its ability to handle multimedia objects
and hypertext links between distributed objects, the Web is
emerging as the most popular means of information access
on the Internet today.
As a hyperlink-based system that uses the client/server
model, the Web organizes Internet resources throughout the
world into a series of linked files, called pages, accessed and
viewed using Web client software, called a Web browser.
Internet Explorer, Firefox, and Safari are three popular Web
