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-10-04-12.pdf

Internet Communications

• Sold by ISPs (Internet Service Providers)– Verizon, Comcast, Cox Cable, etc.

• 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)

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World Wide Web

Web BrowserSoftware that requests and

interprets web pages

Hypertext Transfer ProtocolProtocol for Web Browser and Web Server Communications

Web ServerComputer that holds Web

Pages and handles Browser requests

Web PagesElectronic Documents

Internet

Internet Backbone

• http://maps.level3.com/default/#.UUi-pRw3t2B

• 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