The Web

What is the web?
Does it have to do with these?
  • HTTP
  • Web Servers
  • Web Browsers
  • Web Services
  • Dynamic Webpages
  • Web Applications
  • Frameworks
  • TCP/IP
  • DNS
  • HTML
  • XHTML
  • CSS
  • Javascript
  • AJAX
  • XML
  • JSON
  • Websockets
  • Git/Github
  • Video
  • Audio
  • SVG
  • REST
  • SOAP
  • WSDL
  • XML-RPC
  • CGI
  • Django
  • Flask
  • Application Web Servers
  • Security
  • Performance
  • TLS
  • Web Mining
  • We use the web to request, search, navigate, and share information.
  • We use the web to access and operate software.
  • But really it's more like this...

Demo 1: Firefox

  • Open Firefox
  • Go to a simple webpage like www.cs.ualberta.ca
  • Look at the requests in the developer tools.
  • Show the sourcecode.

Demo 2: HTTP By Hand

  • Open terminal
  • host slashdot.org
  • telnet
    that ip
  • GET /
  • GET / HTTP/1.0
  • GET / HTTP/1.1

The web isn't just for people!

What is the web?

NOT the internet.

The Internet

  • Network of networks of computers
    • desktops
    • laptops
    • phones
    • TVs
    • lightbulbs
    • cars
    • servers

The World Wide Web

  • Network of pages
    • Wiki pages
    • news stories
    • blog posts
    • product descriptions
    • documentation
    • question/answers
    • service resources

What is the web?

NOT the internet.

The Internet

  • Connected with
    • ethernet
    • wifi
    • cable/DSL
    • cell towers
    • satelites
    • undersea cables
    • routers

The World Wide Web

What is the web?

Internet apps

  • multiplayer video games
  • email
  • basic chat apps
  • VoIP (phone calls)
  • Streaming just video/audio

In between

  • gMail
  • Discord

Web Apps

  • Wikipedia
  • Facebook
  • Blogs
  • News Websites
  • Google/DuckDuckGo

Primary Components

  • Webservers
  • Web clients: Web Browsers
  • HTTP
  • HTML

... wait ... what's the HT part?

Hypertext and Hypermedia

By now the word "hypertext" has become generally accepted for branching and responding text, but the corresponding word "hypermedia", meaning complexes of branching and responding graphics, movies and sound – as well as text – is much less used. Instead they use the strange term "interactive multimedia": this is four syllables longer, and does not express the idea of extending hypertext.

Nelson, Literary Machines, 1992

Primary Components

  • Webservers
  • Web clients: Web Browsers
  • HTTP
    • HyperText Transport Protocol
  • HTML
    • HyperText Markup Language
  • Hypertext
    • Text that has links in it.
    • Stuff you can click that takes you somewhere else.

World Wide Web

Forming a huge web (like a spiderweb) of pages from all over the world that you can move around by following links.

Discussion

  • Why is the web different from email?
  • Why is the web different from FTP or gopher?
  • Why is the web different from telnet?
  • Did we need HTTP?

Back to the Wireshark Demo

  • What kind of packets are they?
  • What kind of network do they travel?
  • What kind of layers are we dealing with?

In

  • It should be obvious to you that there are many many many technologies involved.

Resources

License

Copyright 2014-2023 ⓒ Abram Hindle

Copyright 2019-2023 ⓒ Hazel Victoria Campbell and contributors

Creative Commons Licence
The textual components and original images of this slide deck are placed under the Creative Commons is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Other images used under fair use and copyright their copyright holders.

License


Copyright (C) 2019-2023 Hazel Victoria Campbell
Copyright (C) 2014-2023 Abram Hindle and contributors

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