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