Internet Terminology and Summary

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Internet Terminology and Summary
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What is the Internet?

• An interconnected network of thousands of
  networks
• Links academic, research, government, and
  commercial institutions
• Connects computers to about every country in the
  world.
• Growing too fast to measure its growth
• Too decentralized to quantify
• A network with no hard boundaries

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WWW
Chat
Email
File Sharing
Games Music
E- Commerce
Downloading Files
News Groups
Research
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ARPANET Pioneers Build an Unreliable Network ...
on Purpose

• The Advanced Research Projects Agency NETwork
  (ARPANET) is the predecessor to the Internet
• Developed at the request of the Department of
  Defence by a team of visionary computer
  scientists
• Launched in 1969
• Its peer-to-peer networking philosophy and
  protocols were copied in other networks in the
  1980s
• Disbanded in 1990, having fulfilled its research
  mission, but its technology spawned the Internet

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Intranets and Extranets

• Intranets a private network or group of networks
  that are permanently connected and use the
  protocols of the internet and WWW.
• Extranets private TCP/IP networks designed for
  outside use by customers, clients, and business
  partners of the organization which owns the
  extranet. ( An intranet that is accessible from
  locations outside of the physical intranet)

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Internet Protocols

• Protocols are agreed sets of rules that enable
  and control transfer between computers.
• TCP/IP-Transmission Control Protocol/Internet
  Protocol- allows cross-network communication
• FTP- File Transfer Protocol -allows users to
  transfer files
• SMTP Simple Mail Transfer Protocol
• HHTP Hypertext Transfer Protocol
• POP Post Office Protocol

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Packet Switching

• A message is divided into separate packets to
  send over the internet, and is rejoined at the
  receiving end.
• Router- a device that connects two or more
  networks together. It looks data packets coming
  in, and determines which network to send them out
  to.

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Packet Switching
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• TCP breaks messages into packets
• Each packet has all the information needed to
  travel from network to network
• Host systems called routers determine how to
  route transmissions
• IP is the address for the packets
• Each Internet host computer has a unique IP
  address
• Each address is comprised of four sets of numbers
  separated by periods, such as 123.23.168.22

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Internet Access Options

• Dialup Connection
• Limited connection using a modem
• Full access dialup uses SLIP or PPP via modem
• Direct (Dedicated) Connection
• Computer has its own IP address and is attached
  to a LAN
• No need to dial up
• Broadband Connections
• DSL Service
• Newer, faster, and cheaper than ISDN
• Can share phone line with voice traffic
• Cable Modem Connection
• Allows Internet connections using shared TV
  cables
• Can exceed DSL speeds
• Carries increased privacy and security risks

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Internet Access Options

• Satellite Connection
• Provides connection using DirecTV
• satellite dishes
• Wireless Broadband Connection
• Allows multiple computers to connect to a
• base station using short-range radio waves.
• Internet Service Providers (ISPs)
• Local ISPs provide connections through local
  telephone lines
• National ISPs offer connections on a nationwide
  scale

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Internet Servers

• E-mail server acts like a local post office for a
  particular Internet hosta business, an
  organization, or an ISP
• File servers are common within LANs
• Also used to share programs, media files, and
  other data across the Internet
• Application server stores applicationsPC office
  applications, databases, or other applications
• Makes them available to client programs that
  request them
• Might be housed at an application service
  provider (ASP), a company that manages and
  delivers application services on a contract basis
• Web server stores Web pages and sends pages to
  client Web browsers

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Controlling Access to information on the Web

• Firewall -something that monitors all data
  communications and filters any data that it
  determines dangerous. Firewalls can be physical
  devices that are typically located between a
  router and a network switch (e.g.. corporate
  networks), or they can be software that runs on a
  computer (e.g.. home users).
• Cookie small pieces of code that allow web
  authors to interrogate an end users computer
  (e.g. a cookie may keep track of how often a user
  visits a website. It allows personalized content
  to be sent to the end user.
• Proxy Server can serve many purposes
• Act as an intermediary between a companys
  network and the Internet (hides true address of
  workstations within company)
• Cache frequently visited web pages locally. This
  works well with static pages, but not dynamic
  pages like search engines

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Internet Security

• Internet Threats
• Virus a small program created to casue problems
  on network or PC
• Hackers people who try to hack into others
  computers
• Viruses, Worms and Trojan Horses
• Spyware software gathers information about you
  and your family from your computer habits, and
  allows spamming companies to target emails and
  adware to you that better suit your shopping
  needs.
• Adware
• Illegal or Inappropriate content

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Internet Software

• Browser Software- web browsers provide a
  graphical user interface to the resources
  available on the Internet.
• Authoring Software
• Simple plain text editor using HTML ( need
  knowledge of HTML)
• WYSIWYG e.g. Macromedia Front page or
  Dreamweaver
• HTML hypertext markup language

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The Evolving Internet

• Internet2 and the Next Generation Internet
• Internet2 was launched by the government and
  various corporations in 1998 to provide faster
  network communications for universities and
  research institutions
• Next Generation Internet (NGI) will consist of a
  nationwide web of optical fiber integrated with
  intelligent management software to maintain
  high-speed connections

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Internet Issues Ethical and Political Dilemmas

• Filtering software to combat inappropriate
  content
• Digital cash to make online transactionseasier
  and safer
• Encryption software to prevent creditcard theft
• Digital signatures to prevent e-mail forgery
• Access and Censorship
• The Digital Divide

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Lesson Summary

• The Internet is a network of networks that
  connects all kinds of computers around the globe
  and uses standard protocols to allow Internet
  communication to occur
• No single organization owns or controls the
  Internet
• You can connect to the Internet in several ways
  that provide different degrees of access to
  Internet services
• The Web uses a set of protocols to make a variety
  of Internet services and multimedia documents
  available to users through a simple
  point-and-click interface