Download Chapter 12 Summary: The Internet and How It Works

Chapter 12 Summary: The Internet and How It Works
For your review, here’s a summary of the important concepts discussed in this
chapter.
(3)Discuss the origins of the Internet

The Internet began as a research network funded by the U.S. Defense Department
in 1969.

In 1989, the National Science Foundation took over its management, and research
organizations and universities (professors and students alike) became increasingly
heavy users of this ever-growing “Internet.”

Commercial and business use of the Internet was not permitted until 1992, but
businesses have since become its driving force.
(3)Define what a computer network is and how networks are conceptually
structured

A network is a cluster of computers, with one computer acting as a server to
provide services such as file transfer, e-mail, and document printing to the client
computers.

Using gateways and routers, a local area network (LAN) can be connected to
other LANs to form a wide area network (WAN).

These LANs and WANs can also be connected to the Internet through a server
that provides both the necessary software for the Internet and the physical data
connection.
(3)Describe what a computer network is and how the Domain Name System (DNS)
manages the identities of computers connected to the Internet

The Domain Name System (DNS) manages the names and addresses of
computers linked to the Internet.

Computers on the Internet manage names in subdomains that are encapsulated so
that visitors from outside the local network need not worry about the subdomain
names.

When a stream of data is sent over the Internet by your computer, it is first broken
down into packets by the Transmission Control Protocol (TCP).

The IP (Internet Protocol) address is made up of four numbers between 0 and 255
separated by periods.

Domain name servers throughout the Internet quickly look up domain name
addresses and convert them into IP addresses.

For connecting to the Internet through an ISP (Internet Service Provider),
software typically uses a PPP (Point-to-Point Protocol) application for dialing up
and TCP/IP software for properly sending and receiving data once you are
connected.
(3)Define bandwidth and discuss how bandwidth limitations govern the delivery of
multimedia over the Internet

Bandwidth is how much data, expressed in bits per second (bps), you can send
from one computer to another in a given amount of time.

The bottleneck at a typical user’s low-bandwidth modem connection is the most
serious impediment to sending multimedia across the Internet.
(3)Define the most common protocols used on the Internet

http and https for posting and reading documents (from the Hypertext Transfer
Protocol used by the World Wide Web)

pop for receiving electronic mail (from Post Office Protocol)

ftp for transferring files between computers (from File Transfer Protocol)

gopher, for menus of material available on the Internet

usenet for participating in discussion groups (from USErs NETwork)

telnet for logging on and working from remote computers

irc for real-time text messaging (from Internet Relay Chat)

smtp for sending mail (Simple Mail Transport Protocol)

mud for real-time game playing (from MultiUser Dimension).
(3)Define how protocols, MIME-types, and URLs are used to identify, serve, and
deliver multimedia

When a server receives a request, it is handled by a specific application called a
daemon that responds to the request based on the protocol.

The first part of the URL (Uniform Resource Locator) identifies the protocol to
use to handle the request.

Multimedia elements are typically saved and transmitted on the Internet in the
appropriate MIME-type (for Multipurpose Internet Mail Extensions) format and
are named with the proper extension for that type.
(3)Discuss the World Wide Web, HTML, the limitations of HTML, and how various
technologies are stretching the limitations of HTML

The World Wide Web started in 1989 as a “distributed collaborative hypermedia
information system” for linking documents located on computers anywhere
within the Internet.

Hypertext Transfer Protocol (HTTP) provides rules for contacting, requesting,
and sending documents encoded with the Hypertext Markup Language (HTML).

HTML includes structured text mixed with inline images.

HTML’s ability to handle multimedia is limited.

JavaScript and Java applets can add interaction to a page.

Cold Fusion and PHP can work with databases to create web pages on the fly.

XML (eXtensible Markup Language) allows you to create your own tags and
import data from anywhere on the Web.