Studyledge

The Internet and the World Wide Web: Question 3

Syllabus 5.1

Structured 6 marks

A student at Brightwell Academy types "www.brightwell-academy.edu" into the address bar of a laptop that has never visited this website before, then presses enter.

(a) Describe, in the correct order, the steps that take place between the student pressing enter and the school's home page appearing on the screen. Your answer should refer to the domain name server (DNS), the IP address and the web server. [4]

(b) State one reason why computers communicate using IP addresses rather than domain names alone. [1]

(c) The student wants to be able to return to this website quickly tomorrow without retyping the full address. State one feature of the web browser itself that would let them do this. [1]

Show worked solution Hide worked solution

Worked solution

Part (a): The sequence from pressing enter to the page appearing

A URL, such as “www.brightwell-academy.edu”, is a human-readable domain name rather than the numerical address computers actually use to communicate. Retrieving the page therefore happens in a fixed sequence:

  1. Browser sends the domain name for lookup. The browser passes the domain name, “www.brightwell-academy.edu”, to a domain name server (DNS).
  2. DNS returns the matching IP address. The DNS holds a directory matching domain names to IP addresses, and sends back the IP address of the correct web server.
  3. Browser contacts the web server. Using this IP address, the browser opens a connection directly to the school’s web server.
  4. Web server responds and the browser displays the page. The web server sends back the HTML for the home page, and the browser renders this HTML so the page appears on the screen.

Part (b): Why IP addresses are needed

Every device that communicates over a network is identified and located by its IP address. A domain name is only there to make an address memorable for people; computers still need the matching IP address to actually find and connect to the right device, so the domain name must always be translated into one before communication with the web server can take place.

Part (c): Returning to the page quickly next time

Web browsers provide a feature for saving specific addresses that a user wants to revisit easily: bookmarks (also called favourites). Saving “www.brightwell-academy.edu” as a bookmark would let the student open the school’s home page again tomorrow with a single click, without retyping the address into the address bar.

Final answers

  • (a) Browser sends domain name to DNS → DNS returns the IP address → browser contacts the web server using that IP address → web server sends back the page, which the browser displays.
  • (b) Devices are located on a network by their IP address, so the domain name must be translated into one.
  • (c) Bookmarks / favourites.