The Internet and World Wide Webspp2k/1150/008/concepts/L02.pdf · The World Wide Web •Not exactly...
Transcript of The Internet and World Wide Webspp2k/1150/008/concepts/L02.pdf · The World Wide Web •Not exactly...
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 ARPANET – 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/#.UUY45xw3t2A
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)
World Wide Web
Web Browser
Software that requests and interprets web pages
Hypertext Transfer Protocol Protocol for Web Browser and Web Server Communications
Web Server Computer that holds Web
Pages and handles Browser requests
Web Pages Electronic Documents
Internet
15
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
• Ping
• 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)
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
Net Neutrality
• The principle that Internet service providers and governments should treat all data on the Internet equally, not discriminating or charging differentially by user, content, site, platform, application, type of attached equipment, and modes of communication.