Transcript WWWeb - La Salle University

The Internet and WWW
The Internet
o What is the Internet?
o A worldwide collection of networks
o The Internet backbone is the main collection of
networks that carry information from one place to
another (including other countries)
o What are some services found on the Internet?
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World Wide Web (WWW)
E-mail
File Transfer Protocol (FTP)
Newsgroups
Chat rooms
Instant Messaging
History of the Internet
o Where did the Internet come from?
o ARPANET- The original Internet backbone
o Networking project by Pentagon’s Advanced Research
Projects Agency (ARPA)
o Goals- To build a network that wouldo Allow scientists at different physical locations to share
information and work together
o Function if part of network were disabled or destroyed
o Became functional September 1969 and consisted of 4 main
computers. Each of those computers acted as a host.
o A host is any computer that provides services and connections to
other computers on a network.
ARPANET in 1971
ARPANET in 1980
History of the Internet

How has the Internet grown?
Today
More than 150 million host nodes
1984
More than 1,000 host nodes
1969
Four host nodes
History of the Internet
o Who controls the Internet?
o No one- it is a public, cooperative, and
independent network
o Several organizations set standards
World Wide Web
Consortium (W3C)
o Oversees research, sets
standards and guidelines
o Tim Berners-Lee, director
Internet2 (I2)
o Internet-related research and
development project
o Develops and tests advanced
Internet technologies
How the Internet Works

How can you connect to the Internet?
Slow-speed
technology
Dial-up access
modem in your
computer uses a
standard telephone line
to connect to the Internet
Connection must be established
each time you log on.
Slow but inexpensive
High-speed/
Broadband
Digital subscriber line (DSL)Uses regular copper telephone lines
Cable ModemUses the cable TV network
Fixed wirelessAntenna on house communicates
with a tower location
Satellite ModemConnects via a satellite dish
Connection
is
always on—
whenever
the
computer
is running
How the Internet Works
o Access Providers
o A business that provides access to
the Internet free or for a fee
o Usually a fixed monthly payment
o ISP (Internet Service Provider)EarthLink
o OSP (Online Service Provider)- same
as ISP, but includes members only
features. AOL and
MSN, for example)
o WISP (Wireless Internet Service
Provider)- T-Mobile, Verizon Wireless
How the Internet Works
o Internet Addresses
o The Internet relies on an addressing system to send
data to a computer at a specific destination
o IP Address- Internet Protocol Address
o Four groups of numbers, separated by a period. The number in
each group is between 0 and 255.
What is a domain name?
o Text version of Internet
Protocol (IP) address
o Top-level domain- identifies the
type of organization associated with the domain
name
o The Internet Corporation for Assigned Names
and Numbers (ICANN) assigns and controls toplevel domains.
o Domain Name System (DNS)
o The method that the Internet uses to store
domain names and their corresponding IP
addresses
o A DNS server translates the domain name to its
associated IP address so that data can be routed
to the correct computer.
The World Wide Web
o What is the World Wide Web (WWW)?
o A service of the Internet
o A worldwide collection of electronic documents, also
called the Web
o Each electronic document is called a Web page
o Can contain text, graphics, sound, video, and built-in
connections
o A Web site is a collection of related Web pages
The World Wide Web
o What is a Web browser?
o Program that allows you to view Web pages
Mozilla
FireFox
Microsoft
Internet
Explorer
Netscape
The World Wide Web
o What is a home page?
o The first page that a Web site presents
o Often provides connections to other Web pages
The World Wide Web
oHow do handheld computers and cellular telephones
access the Web?
o Use a microbrowser that
displays Web pages that
contain mostly text
o Must be Web-enabled
The World Wide Web
o What is downloading?
o The process of a computer receiving information
o Depending upon connection speed, downloading can
take from a few seconds to several minutes
The World Wide Web
oURL (Uniform Resource Locator)- Unique address for a
Web page
oA web server delivers the Web page to your computer
oHTTP (Hypertext Transfer Protocol)- set of rules that
defines how the pages transfer on the Internet
The World Wide Web
o
What is a hyperlink (link)?
o Built-in connection to another related
Web page location
o Item found elsewhere
on same Web page
o Different Web page
at same Web site
o Web page at a different
Web site
The World Wide Web
o What is a search engine?
o Program used to find
Web sites and Web pages by
entering
words or phrases
called search text
o Also called a keyword
o Many search engines use a
program called a spider to build
and maintain lists of words
found on Web sites.
The World Wide Web
o How to effectively use a search engine
o Use specific nouns and put the most important terms first
o List all possible spellings (for example, email, e-mail)
o Before using a search engine, read its Help info
o Use operators
o Use the space or + operator when you want search results to
display hits that include specific words (ex. Art + Music)
o Use OR operator when you want search results to display hits
that include one word from a list (ex. Dog OR Puppy)
o Use minus operator (-) when you want to exclude a word from
the search results (ex. automobile –convertible)
o Use quotation marks operator when you want to search for an
exact phrase (ex. “19th century literature”)
o Use asterisk operator (*) when you want search results to
substitute characters in place of the asterisk (writer*)
The World Wide Web
o What is a hit?
o Any Web site name that is listed as the result of a search
Step 2.
Select type of
search you want
to run
Step 3. View hits
Step 1. Go to search
engine
Step 4.
Click
link to view
Web site
The World Wide Web
o What is a subject directory?
o Search tool with organized set of topics and
subtopics
o Lets you find information by clicking links rather
than entering keywords
The World Wide Web
o What is multimedia?
o Application integrating text
with other media elements
o Graphics
o Animation
o Audio
o Video
o Virtual reality
The World Wide Web
o What graphics formats are used on the Web?
BMP
Bit Map
GIF
Graphics Interchange
Format
NOT TIFF
Tagged Image
File Format
JPEG
Joint Photographic
Experts Group
PNG
Portable Network
Graphics
The World Wide Web
o What is a thumbnail?
o Small version of a
larger
graphic imageused to improve
Web page display
time
oUsually click
on thumbnail to
display larger
image
The World Wide Web
o What is animation?
o Appearance of motion created by
displaying a series of still images
in sequence
The World Wide Web
o What is audio?
o Music, speech, or any other sound
o Individual compressed sound files
that you download from the Web to
your computer
o Common Web audio file formats
are MP3, WAV, WMA (Windows
Media Audio), MPEG, RealAudio,
and QuickTime
o Once downloaded, you can play
(listen to) the contents of the files
The World Wide Web
o What is streaming audio?
o Transfers data in a
continuous and even
flow
o Enables you to listen
to the sound as it
downloads to your
computer
o Radio stations use
streaming audio to
broadcast over the Web
The World Wide Web
o What is video?
o Consists of full-motion images with sound
played back at various speeds
o MPEG (Moving Pictures Experts Group)
is popular video compression
standard
The World Wide Web
o What is virtual reality (VR)?
o Use of computers to
simulate real or imagined
environment
o Appears as a three
dimensional (3-D) space
o Used for games and
many
practical applications
The World Wide Web
o What are plug-ins?
o Programs that
extend the
capability of
a browser
o You can
download many
plug-ins at no
cost from various
Web sites
Electronic Commerce
o What is e-commerce?
o Short for electronic commerce
o Business transaction that occurs over
the Internet
Business to consumer (B2C)
Sale of goods to general public
Consumer to consumer (C2C)
One consumer sells directly to another
Business to business (B2B)
Business providing goods and
services to other businesses
Other Internet Services
o
What is e-mail?
o Short for electronic mail
o The transmission of messages and files via a computer
network
o Messages can consist of simple text or can contain
attachments, such as documents, graphics, or audio/video
clips
o Internet access providers usually provide an e-mail
program
o Some Web sites—such as MSN Hotmail and Yahoo!—
provide free e-mail services
o One of the original services on the Internet
Other Internet Services
o What is an e-mail address?
o Unique name that consists of a user name
and domain name that identifies the user
Other Internet Services
o How does an e-mail message travel?
Step 1.
Using e-mail
software, you
create and send
message
Step 2.
Your software
contacts software
on your ISP’s
outgoing mail
server
Step 4.
When recipient uses
e-mail software to check
for e-mail messages, the
message transfers from
incoming mail server to
recipient’s computer
Step 3.
Software on outgoing mail server
determines best route for data and sends
message, which travels along Internet
routers to recipient’s incoming mail server
Other Internet Services
o What is FTP?
o File Transfer
Protocol—Internet
standard that allows
you to upload and
download files with
other computers on
the Internet
Other Internet Services
o What is a chat?
o Real-time typed conversation
that takes place on a computer
o Chat room is location on
server that permits users
to discuss topics of interest
o What is instant messaging (IM)?
o A real-time Internet
communications service that
notifies you when one or more
people are online and allows
you to exchange messages or
files
Netiquette
o What is netiquette?
o Code of acceptable behaviors users should
follow while on the Internet
o Golden Rule- treat others as you would like
them to treat you
o For email and chat rooms
o Avoid sending spam, or junk mail
o Use meaningful subject lines
o Be careful when using sarcasm or humor, as it might
be misinterpreted
o Do not assume material is up-to-date or accurate
Creating a Web Site
Identify the goal of the web site
 Who is the audience?
 Create a storyboard

Identify each page in the site
 How are they linked together?

Choose a layout
 Choose a design
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Creating, cont.
Use Dreamweaver to design the site
 Once the layout is complete, add
content (text, images, etc.)
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Publishing the Web Site
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When you create a Web site on your
computer, it will not be available for other
people to see
All of the files for the site have to be
published to a Web Server
 alpha.lasalle.edu
When viewed, they will be at
http://www.lasalle.edu/~smithj1/file.html
Web Server

A Web Server is a computer that runs
special serving software


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It “serves” the Web site files to the client
when requested
When a user opens their browser to view a
Web site, they make a request by entering a
URL
When the server recieves the request, it
sends/serves the page the user wants to
see as well as any related files (images).
HTML Basics
HTML is the computer language that
Web pages are written in
 The Web page itself is just a text
document with instructions for the
browser
 It tells the browser what text to display
on the screen, the location of the files
for the images and where to display
them, etc.

FrontPage

Open FrontPage!