Transcript The Internet and World Wide Web

The Internet, World Wide Web,
and Computer Communication
The Internet
• The Internet is a global system of interconnected
computer networks. It is a network of networks
that consists of millions of private, public,
academic, business, and government networks.*
*Wikipedia
World Wide Web
• A system of interlinked hypertext documents
accessed via the Internet*
*Wikipedia
History of the Internet
• Began with Point-to-Point (P2P)
communication between computers (later
Peer-to-peer)
• First version of the Internet was called
APARNET
– Mainly used by universities,
scientists, and government
agencies to share information
• Internet2
Peer-to-Peer
• P2P – a network where one computer acts as
a server or client for other computers
• Allows sharing access to various resources
such as files
Centralized
(Not P2P)
Internet 2
The Internet
• http://www.cablemap.info/
• http://maps.level3.com/default/#.UUY45xw3t
2A
• http://www.tatacommunications.com/downlo
ads/map/GFP-master_interactive_pdf-10-0412.pdf
Internet Communications
• Sold by ISPs (Internet Service Providers)
– Verizon, Comcast, Cox Cable, etc.
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LAN – Local Area Network
Dial-Up
Broadband
Wi-Fi
Satellite Broadband
Mobile Broadband
Routers and Modems
• Router – forwards data packets over computer
networks to multiple computers
• Modem – (modulator-demodulator) encodes
and decodes transmitted information.
Connects to your ISP.
The Internet
• Every computer or device connected to the
Internet has an IP address
• Instructions on where to send data and where
to receive data
• http://www.whatismyip.com/
VoIP, IM, Video Chat
• Voice over IP
• Alternative to traditional telephone
• Ventrilo, Teamspeak, Raidcall
• Skype, Google Hangouts, Facetime
The Internet
Internet users by Language
Website content language
Internet - Domain Names
• Defines a realm of administrative autonomy,
authority, or control
• US Department of Justice began using a tactic
of seizing domain names, based on the legal
theory that domain names
are part of the property used
by defendants to allegedly
engage in criminal activities,
and thus subject to forfeiture
The World Wide Web
• Not exactly the same as the Internet
– Internet is a system of interconnected computer
networks
– World Wide Web is a collection of text documents
and other resources linked by hyperlinks and
URLs( Uniform Resource Locator)
World Wide Web
Internet
Web Server
Computer that holds Web
Pages and handles
Browser requests
Web Browser
Software that requests and
interprets web pages
Hypertext Transfer Protocol
Protocol for Web Browser and
Web Server Communications
Web Pages
Electronic Documents
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Internet Backbone
• http://maps.level3.com/default/#.UUipRw3t2B
• http://www.verizonenterprise.com/ca/about/
network/
Google Data Centers
Computer Communications
• Information broken into packets
• To avoid monopolizing a network
• To recover in an event of an interruption
Computer Communications
• Bandwidth – the available or consumed data
communication resources expressed in bits
per second
• Latency – Time
delay between
communications
• Speedtest
Torrents
• Torrent file – a computer file that contains
metadata about files and folders to be
distributed, and usually also a list of the
network locations of trackers
• Uses Peer-to-peer connections (P2P)
Magnet Links
• Trackers/hash code for the files are within the
link
• Don’t need to download Torrent file anymore
Proxy Servers and VPN
• User connects to a proxy server as an
intermediary to another server
– i.e. Connect to a proxy server from another
country
• VPN – virtual private network: allows
computer to send and receive across shared
or public networks as if it were directly
connected to the private network