1.8 Web Browser
Let's dive deep into the world of web browsers! A web browser is your gateway to exploring websites on the Internet. You just enter the web address (URL), and the browser fetches the website for you. Think of the browser as a friendly guide that helps you visit places (websites) on the World Wide Web.
Key Points from the Content
1. Web Browser: Definition and Features
A web browser is a software application used to visit different websites. It acts as an interface between the user and the World Wide Web. Browsers support navigation between files, folders, and websites through clickable links known as hyperlinks.
Features offered by web browsers:
- Downloading files from the Internet.
- Saving favorite sites with bookmarks.
- Managing usernames and passwords.
- Performing spell checks.
- Adding search engine toolbars.
- Tabbed browsing – opening multiple sites in a single window.
- Filtering advertisements and blocking annoying pop-ups.
- Supporting both graphical (pictures, videos) and text-based interfaces.
Popular web browsers:
- Google Chrome
- Mozilla Firefox
- Microsoft Internet Explorer (MSIE)
- Opera
- Apple Safari
- Microsoft Edge
Elaboration and Examples:
- When you click a hyperlink, such as a news headline, the browser takes you to the full story—this is navigation with hyperlinks.
- If you want to revisit your school’s website quickly, you can create a bookmark for it.
- Downloading your class assignment from the school portal is another function your browser performs.
2. GUI Based Browser
A GUI-based browser (Graphical User Interface) lets you view not just text, but also images, videos, and interactive animations. You navigate by pointing and clicking, making it simple and enjoyable.
Important points:
- Browsers like Chrome, Firefox, and Safari are GUI-based.
- They require more bandwidth and CPU power because loading images or videos is more intensive than loading just text.
- Content seems richer and more engaging.
Examples:
- Watching educational videos on YouTube via Chrome.
- Viewing pictures and animations on NASA’s website using Firefox.
- Reading news articles with images on Safari.
3. Text Based Browser
A text-based browser only shows text. It doesn’t display images, videos, or animations. You use keyboard keys to move between links.
Important points:
- Useful for users who prefer or require only text, like the visually impaired who use screen readers.
- They use less data, so are appropriate for slow Internet connections.
- Example: Lynx is a popular text-based browser.
Examples:
- Browsing Wikipedia on Lynx, where you only see text and no images.
- Using a text-based browser to check university announcements with very little Internet bandwidth.
- Visually impaired users can use speech synthesizers with text-based browsers.
Fun Activity: Try using a text-based browser like Lynx!
Activity: Exploring a Website Using Lynx
Step-by-step Instructions:
- Download and install Lynx (with the help of your teacher or on a school computer).
- Open Lynx and type the URL of any website, like “www.wikipedia.org”.
- Use the up and down arrow keys to move between underlined links.
- Press Enter to visit a selected link.
- Observe how quickly text loads.
Observations:
- No images or ads appear. Only clean, readable text.
- Websites load much faster.
- Perfect for quick reading and low-data usage.
4. Web Address (URL) and Its Elements
A URL (Uniform Resource Locator) is the global address of any document or resource online. It’s like the website’s home address.
Elements of a URL:
- Scheme/Protocol: Indicates how information is transferred. Common examples:
https, http, ftp, mailto.
- Host: The location of the web server, often starts with ‘www’.
- Domain: The unique name of the website. It’s easier to remember than a long IP address!
- Path: Specifies the particular page or resource being requested.
Examples:
- For
https://www.india.gov.in/india-glance/states-india
- Scheme:
https
- Host:
www
- Domain:
india.gov.in
- Path:
india-glance/states-india
- For
mailto:principal@school.edu
- Scheme:
mailto
- Host and Domain:
school.edu
- Path: This is not used as it's an email.
5. Common Domain Extensions
Domain extensions tell us more about websites. They give clues about the type or origin.
Popular Extensions:
| Entity | Domain Extension |
|---|
| Commercial | .com |
| Governmental | .gov |
| Organisation | .org |
| Information | .info |
| U.S. military | .mil |
| Mobile devices | .mobi |
| International organisations | .int |
| Network | .net |
| Educational | .edu |
| Business | .biz |
| Asia-Pacific region | .asia |
| Air-transport industry | .aero |
Country Codes:
- India:
.in
- Pakistan:
.pk
- United States:
.us
- United Kingdom:
.uk
- Japan:
.jp
- France:
.fr
Examples:
- The website for Harvard University is
www.harvard.edu (.edu indicates education).
- The Government of India’s official site is
india.gov.in (.gov for government, .in for India).
- Facebook is
www.facebook.com (.com for commercial).
Activity: Understanding DNS with an Analogy
Analogy: Imagine your friend’s names in your phone. When you want to call "Amit", you click on his name but the phone dials his number. Similarly, the Domain Name System (DNS) converts the easy-to-remember website names into the numerical IP addresses required to fetch data from the web.
Step-by-step Instructions:
- Imagine you call a friend using their name in your contacts.
- Your phone automatically finds the correct phone number and makes the call.
- Similarly, when you type
www.google.com in the browser, DNS finds the correct IP address.
- The browser connects to that IP to display Google’s page.
Observations:
- Names are easier to remember than numbers.
- DNS makes browsing the web more convenient.
- Every website "name" you use is mapped behind the scenes to a unique "number" (IP address).
Scenario-Based Questions
-
Scenario: You have slow internet on your school’s computer.
- Question: Which type of browser should you use to access information quickly, and why?
- Answer: Use a text-based browser like Lynx because it loads only text, requiring less data and loading faster.
-
Scenario: You want to access an educational website for your homework.
- Question: How can you identify if a website is meant for education by looking at its URL?
- Answer: Look for the domain extension
.edu which suggests the site belongs to an educational institution.
-
Scenario: You need to show a video to your friends in the computer lab.
- Question: Which browser interface is best suited for this task?
- Answer: Use a GUI-based browser like Chrome or Firefox, as they can display videos and pictures.
-
Scenario: You are curious about an international organization’s official site.
- Question: Which domain extension should you expect to see?
- Answer: Look for
.int, which stands for international organizations.
-
Scenario: You typed the address https://www.nasa.gov/mission_pages/station/main/index.html in your browser.
- Question: Break down the elements of this URL.
- Answer:
- Scheme:
https
- Host:
www
- Domain:
nasa.gov
- Path:
mission_pages/station/main/index.html
Remember: Web browsers make the world of the Internet accessible and exciting. Explore wisely and safely!
