The Internet - Suny Cortland
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Transcript The Internet - Suny Cortland
The Internet
The Internet: A Definition
Short for Internetwork
AKA: The World Wide Web, or the Net
This is defined by the system of communications channels
Cable
Satellite
Fiber Optics
Telephone
A Network of Networks
Connected by a common set of rules: TCP/IP
Populated by services:
WWW, Communications, Data Transfer
History
Advanced Research
Projects Administration
From Dept of Defense
Funding of
Communications resources
First to Universities and
Tech Companies
UCLA & SRI Int’l – 10/29/69
UC Santa Barbara, U. of Utah
Went international in the
70s
UK, Sweden, Norway
Wikipedia, 2012
History… continued
1980s
National Science Foundation 1981
CompuServe, America Online,
Prodigy
Email, live chat, remote access to
databases
1989 – Tim Berners Lee – Hyper
Text Markup Language
1990s
Public can surf the web
with Web Browsers
TCP/IP standardized
Protocols that make
communications possible
NSF Net expanded to allow
access to supercomputers –
1985
Commercial usage
Protocols for graphical display of
the World Wide Web
Dial-Up services and special
Web Browsing software
Had to pay for each
Uses in business, gaming,
personal life, communications
Huge impacts!
eComerce, eMail,
eCommunications, eActivism
So Many eThings!
The World Wide Web
Public can surf the web with Web Browsers
1993 – Mosaic Graphical Web Browser
1994 – Netscape Navigator
1995 – Microsoft Internet Explorer
1996 – Opera (mostly used on mobile devices now)
1998 – Netscape becomes Mozilla Firefox
2003 – Apple Safari
Became and remains the #1 browser
Bundled with Windows (#1 Operating System)
Bundled with the computer
2008 to 2010 – Google Chrome
How Does It Work?
1.Client Web Browser
1. URL
2. Browser sends DNS
request
2.DNS
returns IP
3.Browser sends “GET” to
IP
4.ISPs take packets of data
through many routers and
networks
5.Server receives GET and
returns packets of data
6.Again, networks
7.Local machine receives
requested data
(2010, HowStuffWorks.com)
The Internet
Top of the screen is a Address Bar
This defines the URL of the website or file currently being
explored
URL: Universal Resource Locator
essentially like a street address but it doesn’t refer to an actual physical
location, but a file location on a server or in a directory
http://www.nytimes.com/gst/mostpopular.html/
Hyper Text
Transfer
Protocol
Domain Name
As registered
with a Domain
Name Serivce
Top-Level
Domain
Defining type
of domain
Path or
subdirectory and
actual page file
How does this work?
Hyper Text Markup Language:
A simple programming language that universally tells a web browser how to set up and define a web page
Gives formatting and parameters for display
A simple web site
Open notepad
Enter in the text
Save As:
Simple.html
To your INSM180
folder
Open with a web
browser
Should automatically
choose this
<html>
<head>
<title>A simple web page</title>
</head>
<body>
This is a really simple Web Page!
</body>
</html>
Navigating the Internet
Very large with well over 10 billion registered websites
Also full of questionable content
Identify some useful Search Engines:
http://www.yahoo.com/
http://www.ask.com/
http://www.google.com/
http://www.bing.com/
Let’s compare these web search
engines…
Everyone choose at least one of these services
You can open multiple tabs at the top of the web browser
content frame
Brainstorm topic:
Type keywords into search bar and hit enter
Describe top 5 returned items
What are they?
Do they want money? Personal info?