The internet
On this page 8 topics
Overview
Topics
- Internet vs web
- IP addresses
- domains
- DNS
- browsers
- clients and servers
- requests and responses
- HTTP vs HTTPS
Learn first
95 min of reading · 1.5 h of practice (estimate)
Learning outcomes
- Distinguish the internet (the network) from the web (one service that runs on it).
- Trace what happens from typing a URL to seeing a page: DNS lookup, connection, request, response, rendering.
- Look up a domain's IP address with
nslookupand explain the result. - Explain what HTTPS adds over HTTP and why it matters.
Lessons
- 01Internet vs web13 min read
- 02IP addresses and ports13 min read
- 03Domains and DNS13 min read
- 04Clients, servers, requests, and responses14 min read
- 05HTTP vs HTTPS: what encryption protects13 min read
- 06Watching a request in the browser's developer tools14 min read
- 07Demo: following a URL with nslookup and the Network tab15 min read
Lab and exercises
Lab
BEG-003-LAB1 · Follow a request
Outcomes: 2, 3 · Time: ~1 h
- Run
nslookupon three domains and record the IP addresses. - Open a site with the browser's Network tab open and reload.
- Find the main document request; record its method, status code, and type.
Acceptance: screenshots plus labeled answers.
Exercises
| ID | Outcome | Task |
|---|---|---|
| BEG-003-EX01 | 1 | List two internet services that are not the web. |
| BEG-003-EX02 | 2 | Write, in order, the steps from typing a URL to seeing the page. |
| BEG-003-EX03 | 2 | Explain the difference between an IP address and a port. |
| BEG-003-EX04 | 3 | Run nslookup on a domain of your choice. Which line holds the IP address? |
| BEG-003-EX05 | 3 | Why can one domain return several IP addresses? |
| BEG-003-EX06 | 4 | State two things HTTPS adds over HTTP. |
| BEG-003-EX07 | 4 | True or false, with a reason: HTTPS hides which site you visit. |
Show solutions
- EX01 Email, video calls, online games, file transfer.
- EX02 URL typed → DNS lookup → connect to the server → send request → server sends response → browser renders the page.
- EX03 IP identifies the computer; the port identifies the service on it.
- EX04 The "Address" line(s) after the name in the answer section.
- EX05 The site may run on several servers for capacity and reliability.
- EX06 Encryption in transit, and proof that you reached the real site.
- EX07 False. The domain can still be seen; only the content is encrypted.
Quiz
Outcomes: O1 internet vs web · O2 URL to page · O3 nslookup · O4 HTTPS.
A self-check for you: nothing is graded, saved or sent anywhere. Choose an answer, then check it. You can try again as often as you like.
Practical part
Draw and narrate the URL-to-page sequence diagram: browser, DNS, server, with each step labelled. Pass: all five steps in order.
Common mistakes
Thinking a domain is a server; believing HTTPS hides which site you visit; confusing IP address and port.
Assessment
Draw and narrate the URL-to-page sequence diagram.
Career relevance
Foundation for BEG-052, JNR-017, and every networking topic through ARC-013.