Week 6 - The WWW Flashcards
Name 3 web fundamentals?
- Pages made from HTML.
- Links/ images as anchors.
- Links allow progression of pages.
What kind of model is the WWW?
- A client-server system.
* Content held by web servers & requested by client.
Describe the HTTP protocol?
Hypertext Transfer Protocol
- Client opens TCP connection to web server, sends HTTP header.
- Header contains command (get, put, post).
- Also contain authentication info, cookies.
Name the 4 HTTP commands?
- GET - retrieve page.
- PUT - upload files.
- POST - client sends results.
- HEAD - same as GET, no response body.
What is the advantage of HTTP being a stateless protocol?
• Hosts don’t need to retain info about users.
What is the disadvantage of HTTP being a stateless protocol?
• Forces web developers to use alternative methods for maintaining users’ states.
Describe what state information is?
• Things about the user to improve website usability.
What are cookies?
- Piece of text that a web server stores on hard disk.
* Stored as name-value pairs.
How does a cookie work?
- When user types a URL, machine looks for cookie if website has been previously visited.
- If pair found, machine sends to browser to be used.
- If no pair found, machine creates pair for URL.
What are cookies used for?
• Sites see how many users visited their site.
• Sites customised to user-specific.
Used for shopping carts.
Name 5 problems with cookies?
- Public/ shares machines won’t know different users.
- Cookie information not permanent.
- Users have multiple machines.
- Cross-site profiling.
- Sell your information.
What are third-party cookies?
- Advertising companies use this to track users across sites.
- Used to target ads at users.
What is HTTPS?
- The secure version of HTTP.
- Authenticates websites.
- Protects against eavesdropping.
- Prevents in-transit attacks.
What are some problems with HTML?
• Rapid invention of new elements caused interoperability problems on different platforms.
