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Level 1 · Digital Foundations · Course 1.2 Networking and the Internet

Module 6: How the Web Works

Goal: follow what really happens between typing a web address and seeing the page, and learn to watch it happen in your own browser.

You'll need: a computer with Chrome, Edge or Firefox.

Lessons

  1. 1Domains and DNS15–25 minutes✓
  2. 2Browsers15–25 minutes✓
  3. 3Requests and responses (HTTP)15–25 minutes✓
  4. 4HTTPS and the padlock15–25 minutes✓
  5. 5What happens when you type a web address15–25 minutes✓

🛠️Module practice: watch a page load

Using your test site or any site you like:

  1. Run nslookup on its domain and note the IP address.
  2. Load it with the Network tab open. Note the number of requests and the status of the first one.
  3. View its certificate: who issued it and when it expires.
  4. Use Inspect to temporarily change one heading on your screen.

✅Module check

Explain in a few sentences, in your own words:

What happens between typing a web address and seeing the page?

Show a good answer

A good answer mentions: DNS turns the domain into an IP address; the browser connects to the server (port 443 for HTTPS) and sets up encryption, checking the certificate; it sends an HTTP GET request; the server responds with a status code (200 OK) and the HTML; the browser then requests the CSS, scripts, images and fonts the page needs, and paints the page.

📝Module quiz

10 questions · 10 marks each · 100 marks in all · pass mark 70% · retry as often as you like ·

1. You created test.prolearners.in. What is test?

Why each option is right or wrong

  • “A separate domain name that you had to buy on its own” (Incorrect): You bought prolearners.in once. Names under it don't need buying again.
  • “The name of the web browser used to open the test site” (Incorrect): Browsers are programs like Chrome; they aren't part of a web address.
  • “The IP address of the server that hosts the test site” (Incorrect): IP addresses are numbers like 49.36.10.5. DNS links the name to that number.
  • “A subdomain you create under a domain you already own” is correct.

    Owning prolearners.in lets you make any number of names under it, such as test, shop or api. Each is a subdomain, and each can point to a different server with its own DNS record.

    • No extra purchase: subdomains are free; you just add a DNS record.
    • Common use: test.yoursite.in for a trial version, so the main site stays untouched.

📖 Revise: Lesson 1: Domains and DNS

Question ID module-06-q1 · Report a mistake in this question
2. A website stops working the day after its yearly renewal date. What should you check first?

Why each option is right or wrong

  • “Whether the server's disk filled up during the night” (Incorrect): Possible in general, but the timing matching the renewal date points to the domain first.
  • “Whether visitors need to clear their browser cache” (Incorrect): A cache can show old pages, but it can't make a whole site vanish for everyone on one particular date.
  • “Whether the CSS file grew too big for the server to send” (Incorrect): A large CSS file makes pages slower; it doesn't make the site disappear on a renewal date.
  • “Whether the domain registration was renewed” is correct.

    Domains are rented for a fixed period. If the renewal isn't paid, the registrar stops pointing the name at your server, and visitors can't reach the site even though the server is fine.

    • The clue: the timing matches the renewal date exactly.
    • Prevent it: turn on auto-renew and keep the registrar's contact email up to date.
    • Act fast: after a grace period, an expired domain can be bought by someone else.

📖 Revise: Lesson 1: Domains and DNS

Question ID module-06-q2 · Report a mistake in this question
3. Which part of a web page controls its colours?

Why each option is right or wrong

  • “HTTP, the protocol that carries the page” (Incorrect): HTTP carries files between server and browser; it doesn't decide how they look.
  • “HTML, the tags that describe the content” (Incorrect): HTML describes structure. Colours belong in CSS, even though old HTML once mixed them in.
  • “DNS, which looks up the website's address” (Incorrect): DNS turns names into addresses; it has nothing to do with appearance.
  • “CSS” is correct.

    Web pages are built from three layers: HTML gives the structure and content, CSS controls appearance such as colours, fonts and layout, and JavaScript adds behaviour.

    • HTML: what's on the page (headings, paragraphs, images).
    • CSS: how it looks.
    • JavaScript: what happens when you interact.

📖 Revise: Lesson 2: Browsers

Question ID module-06-q3 · Report a mistake in this question
4. You edited a website's text using the browser's Inspect tool. Did you change it for everyone?

Why each option is right or wrong

  • “Only for people in your city who load the page next” (Incorrect): Edits in Inspect stay in your browser, so location doesn't matter.
  • “Yes, permanently, for everyone who visits the website” (Incorrect): The server's files are untouched. Only someone with access to the server can change the real page.
  • “Yes, until midnight, when the site resets to its saved version” (Incorrect): There's no midnight reset. Your edit vanishes as soon as you refresh.
  • “No, only your browser's copy; refreshing reloads the real page” is correct.

    The browser downloads a copy of the page and builds it in memory. Inspect lets you edit that copy to experiment, but nothing is sent back to the server, so nobody else sees it and a refresh brings back the original.

    • Great for trying ideas: test a colour or a wording before changing the real files.
    • Watch out for fakes: screenshots of 'edited' pages are easy to forge this way.

📖 Revise: Lesson 2: Browsers

Question ID module-06-q4 · Report a mistake in this question
5. You submit a contact form. Which HTTP method is most likely used?

Why each option is right or wrong

  • “DELETE, because the form clears itself after sending” (Incorrect): DELETE asks the server to remove something. A cleared form is just the page resetting.
  • “PING, because the browser checks the server is awake first” (Incorrect): Ping is a network tool, not an HTTP method.
  • “GET, because every request to a website uses it” (Incorrect): GET fetches pages, but sending form data is POST's job.
  • “POST, because you're sending data to the server” is correct.

    HTTP methods describe the intent of a request. GET asks for something; POST sends data for the server to process, such as a form submission.

    • GET: fetch a page or data; shouldn't change anything.
    • POST: create or submit something.
    • Privacy bonus: POST puts data in the request body, not the address bar or browser history.

📖 Revise: Lesson 3: Requests and responses (HTTP)

Question ID module-06-q5 · Report a mistake in this question
6. A user sees "404" on your site. What does it mean?

Why each option is right or wrong

  • “The user's Wi-Fi is off, so the page couldn't arrive” (Incorrect): With Wi-Fi off, no server could answer at all, so there'd be no 404.
  • “The server is completely down and not responding at all” (Incorrect): A down server can't send a 404. Someone had to answer to say 'not found'.
  • “The domain has expired and now points to nowhere” (Incorrect): An expired domain usually gives a DNS error, not a 404 from your server.
  • “The server answered but couldn't find that page” is correct.

    A 404 is a response from your server. It's working; it just has nothing at the requested address, often because of a typo, a deleted page or a broken link.

    • 4xx codes: the request has a problem (404 not found, 403 forbidden).
    • 5xx codes: the server has a problem (500 internal error).
    • Fix: correct the link, or redirect old addresses to new ones.

📖 Revise: Lesson 3: Requests and responses (HTTP)

Question ID module-06-q6 · Report a mistake in this question
7. A website shows a padlock. What does that prove?

Why each option is right or wrong

  • “The site has been checked and approved by the government” (Incorrect): No government approves sites through the padlock.
  • “The site is completely trustworthy and safe to pay on” (Incorrect): The padlock protects the connection, not your judgement about who runs the site.
  • “The site's code has been tested and has no bugs” (Incorrect): Certificates have nothing to do with code quality.
  • “The connection is private and the domain is genuine, nothing more” is correct.

    The padlock means HTTPS: traffic between you and the site is encrypted, and the certificate proves you're connected to the domain shown in the address bar. It says nothing about whether the people running that domain are honest.

    • Scammers use HTTPS too: certificates are free and automatic.
    • Read the domain every time: prolearners-login.co can have a padlock and still be fake.

📖 Revise: Lesson 4: HTTPS and the padlock

Question ID module-06-q7 · Report a mistake in this question
8. Which order is right when you open a web address?

Why each option is right or wrong

  • “Encrypt → paint → look up the IP → request the page” (Incorrect): You can't encrypt a connection to a server you haven't found yet, or paint a page you haven't received.
  • “Request the page → look up the IP → paint → encrypt the result” (Incorrect): The request needs an address and a secure connection first.
  • “Paint the page → request it → look up the IP → encrypt it” (Incorrect): Nothing can be painted before the page has arrived.
  • “Look up the IP (DNS) → set up encryption (TLS) → request the page → paint it” is correct.

    The browser must first find the server, then secure the connection, then ask for the page, and only then can it draw anything.

    • DNS: turns the name into an IP address.
    • TLS handshake: agrees encryption keys and checks the certificate.
    • HTTP request: asks for the page.
    • Render: reads HTML, fetches CSS, images and scripts, then paints the screen.

📖 Revise: Lesson 5: What happens when you type a web address

Question ID module-06-q8 · Report a mistake in this question
9. The page loads but looks plain, without its fonts and colours. Which step most likely failed?

Why each option is right or wrong

  • “The browser's installation, which needs repairing first” (Incorrect): The browser loaded and displayed the HTML, so it's working.
  • “The encryption handshake, which failed halfway through” (Incorrect): If the handshake failed, no part of the page would load.
  • “The DNS lookup for the domain, which returned nothing” (Incorrect): If DNS failed, the browser couldn't reach the server at all.
  • “A follow-up request for the CSS or font files” is correct.

    The HTML arrived, so DNS, encryption and the main request all worked. Styles come in separate files the page asks for afterwards. If one of those requests fails, the content shows without its design.

    • Check: DevTools → Network tab; look for red rows (404 or blocked).
    • Common causes: a wrong file path, a file not uploaded, or a typo in the link tag.

📖 Revise: Lesson 5: What happens when you type a web address

Question ID module-06-q9 · Report a mistake in this question
10. A login page shows "Not secure" in the address bar. Should you type your password?

Why each option is right or wrong

  • “Yes, if the page looks professional and well designed” (Incorrect): Design can be copied in minutes. It says nothing about encryption.
  • “Only when you are using mobile data instead of Wi-Fi” (Incorrect): Mobile data doesn't encrypt your traffic to the website. Only HTTPS does.
  • “Yes, as long as you trust the company that runs the site” (Incorrect): Trust in the company doesn't protect the data on its journey.
  • “No, without HTTPS it could be read on the way” is correct.

    "Not secure" means the page uses plain HTTP. Anything you type travels unencrypted, so anyone on the same network, such as public Wi-Fi, could capture it.

    • Rule: no HTTPS, no passwords or card numbers.
    • Also a warning sign: genuine services almost all use HTTPS now, so its absence may mean a fake page.

📖 Revise: Lesson 4: HTTPS and the padlock

Question ID module-06-q10 · Report a mistake in this question

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