Learning Objectives
- Describe the complete process that begins when a user enters a URL.
- Explain the roles of the browser, IP address, DNS, web server and HTML.
- Distinguish name resolution from page retrieval and rendering.
- Write a logically ordered examination answer for the process.
Key Terms
- DNS
- Domain Name Server system that translates a domain name into the corresponding IP address.
- IP address
- A network address used to identify the destination device or server.
- Web server
- A system that stores web resources and responds to browser requests.
- HTML
- Markup used to describe the structure and content of a web page.
- Resolution
- The process of finding the IP address associated with a domain name.
- Retrieval
- Requesting and receiving the required web resource.
- Rendering
- Interpreting HTML and producing the displayed page.
- Packet
- A unit into which transmitted data is divided for movement across networks.
Stage 1: The Browser Interprets The URL
The process begins when the user enters a URL into the browser address bar or follows a hyperlink. The browser examines the URL to identify the protocol, the domain name and the requested page or file.
The browser needs an IP address to direct communication to the correct destination. People commonly use domain names because they are easier to remember, but network communication relies on addresses that identify devices and servers.
Stage 2: DNS Resolves The Domain Name
The browser or operating system obtains the IP address associated with the domain name by using the domain name server system. A DNS server receives a query containing the domain name and returns the corresponding IP address when it can resolve the name.
DNS does not normally send the requested web page. Its role in this process is name resolution. This distinction is frequently tested: DNS supplies or helps locate the IP address, while the web server supplies the web resource.
Stage 3: The Browser Requests The Resource
Using the IP address, the browser can send an HTTP or HTTPS request towards the web server. The request identifies the required page or file from the URL. The data travels through the internet infrastructure and may be divided into packets.
The web server receives the request and locates the requested resource. It then sends a response. For a page, the response commonly includes HTML. If the resource cannot be supplied, the server can return a status response rather than the requested page.
Stage 4: The Browser Renders The Page
The browser receives the response and interprets the HTML. It creates the page structure and displays the content. If the HTML refers to separate resources, the browser may make additional requests for them.
The completed display is therefore the result of several distinct roles: the URL identifies the resource, DNS provides the server IP address, the internet carries the communication, the web server returns the resource, and the browser renders the HTML.
Writing The Process In The Correct Order
A strong answer follows the sequence from URL to display. It does not jump directly from typing a domain name to seeing the page. Each named component must be connected to an action.
Useful verbs include: the browser parses the URL; DNS resolves the domain name; the browser sends a request to the server IP address; the web server returns HTML; the browser renders the HTML and displays the page.
Roles In Page Retrieval
| Component | Role |
|---|---|
| Web browser | Accepts the URL, sends the request, receives the resources and renders HTML |
| IP address | Identifies the network destination of the web server |
| DNS | Translates or resolves the domain name into an IP address |
| Web server | Stores the resource and sends a response to the browser |
| HTML | Describes the page structure and content that the browser renders |
Worked Examples
Ordering The Stages
Question: Put these events in order: web server returns HTML; DNS returns an IP address; browser displays the page; user enters a URL; browser requests the page.
- Begin with the user action.
- Resolve the human-readable domain name before addressing the server.
- Send the request after the destination address is known.
- Receive the resource before rendering it.
Answer: User enters URL → DNS returns the IP address → browser requests the page → web server returns HTML → browser renders and displays the page.
Correcting The Role Of DNS
Question: A student says, “The DNS sends the website to the browser.” Explain the correction.
- State the actual purpose of DNS.
- Identify the component that stores and sends the page.
Answer: DNS resolves the domain name to an IP address. The browser then requests the page from the web server, which returns the HTML or other resource.
Examination Guidance
- Name every component requested in the question and attach a correct action to it.
- Maintain chronological order from URL entry to page display.
- Do not say that DNS stores all websites; it resolves names to IP addresses.
- End the process with the browser rendering HTML, not merely receiving data.
Common Mistakes
- Saying the URL is converted directly into HTML.
- Giving DNS the role of the web server.
- Forgetting the IP address.
- Saying the web server renders the page for the user.
- Writing an unordered list rather than a connected process.
Knowledge Check
1. What is the role of DNS when a user enters a URL?
2. Why is an IP address needed?
3. Which component normally sends the HTML page?
4. Which component renders the HTML?
5. Why may the browser send more than one request for a page?
