CMPUT 404

Web Applications and Architecture

Part 02: Overview

Created by
Abram Hindle (abram.hindle@ualberta.ca)
and Hazel Campbell (hazel.campbell@ualberta.ca).
Copyright 2014-2019.

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: Wireshark

  • Open wireshark
  • Open Firefox
  • Go to a simple webpage like www.cs.ualberta.ca
  • Show the packets

Demo 3: 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 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

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 can you 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 2022

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

Resources

License

Copyright 2014 ⓒ Abram Hindle

Copyright 2019 ⓒ 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

The source code to this slide deck is: 

          Copyright (C) 2018 Hakim El Hattab, http://hakim.se, and reveal.js contributors
          Copyright (C) 2019 Hazel Victoria Campbell, Abram Hindle and contributors

          Permission is hereby granted, free of charge, to any person obtaining a copy
          of this software and associated documentation files (the "Software"), to deal
          in the Software without restriction, including without limitation the rights
          to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
          copies of the Software, and to permit persons to whom the Software is
          furnished to do so, subject to the following conditions:

          The above copyright notice and this permission notice shall be included in
          all copies or substantial portions of the Software.

          THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
          IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
          FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
          AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
          LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
          OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN