Internet Basics

Objectives

  • Understand how the internet works(high level)
  • Understand the difference between front-end and back-end
  • View the HTML on any given website

How the Internet Works

http://

www.udemy.com

/courses

Finding the Right Address

  • Your query is submitted to your ISP
  • Within your ISP, the DNS takes the Domain name and turns it into an IP address

23.235.47.175

www.udemy.com

Going to that Address

  • A request is sent to the desired IP address via HTTP
  • Your request finds the fastest path possible path to the server with the specified IP
  • This is not a direct journey.  It requires hoping from server to server until we arrive

23.235.47.175

www.udemy.com

Udemy Server Responds

  • The requested server figures out exactly what we're asking for(/courses)
  • The server builds us the right content, often pulling information from database
  • The server responds with any combination of HTML, CSS, and JavaScript
  • And then...

23.235.47.175

www.udemy.com

View Page Source

  • We can view the underlying HTML, CSS, and Javascript on any webpage
  • In Chrome, right click and select "View Page Source"
  • Or select View > Developer > View Source
  • Or use the shortcut COMMAND + OPTION + U