Year 7 Digital Technologies · Digital Systems · 9m read

Networks and the Internet

Ever wondered how your message reaches your friend's phone in seconds, even if they're on the other side of the world? Networks are systems of connected devices that share information using agreed-upon rules called protocols—think of them as a universal language that computers use to understand each other. Learning how data travels across the internet helps you understand everything from cybersecurity to how online services actually work, skills you'll need for modern life and most VCE computing courses.

Learning objective: Describe how networks function, how data is transmitted and the role of protocols.

By the end of this lesson you can:

I distinguish LAN, WAN and the Internet.
I explain how data packets travel across a network.
I describe the roles of IP addresses and protocols.

Networks — types, components and protocols

NETWORK: two or more devices connected to share data and resources.

TYPES OF NETWORKS:
LAN (Local Area Network): small area — home, school, office. Typically wired (Ethernet) or Wi-Fi.
WAN (Wide Area Network): large area — cities, countries. Uses telephone lines, fibre optic cables.
THE INTERNET: the world's largest WAN — a global network of networks.

NETWORK HARDWARE:
ROUTER: directs data between networks. Connects your home/school to the internet.
SWITCH: connects devices within a LAN and directs data to the right device.
MODEM: converts digital signals to analogue (and back) for transmission over phone lines.
SERVER: a computer that stores and provides resources to other devices (clients).

DATA TRANSMISSION:
Data is broken into PACKETS (small chunks).
Each packet contains: data + source IP + destination IP + packet number.
Packets travel INDEPENDENTLY through the network (may take different paths).
At the destination, packets are REASSEMBLED in order.
This is called PACKET SWITCHING — efficient and resilient.

IP ADDRESS: unique address for every device on a network.
IPv4: 4 numbers, e.g. 192.168.1.1 (about 4 billion addresses).
IPv6: newer, longer format (trillions of addresses).

PROTOCOLS: agreed rules for communication.
HTTP/HTTPS: web pages. HTTPS = encrypted (secure).
FTP: file transfers.
TCP/IP: fundamental rules for all internet communication.
DNS (Domain Name System): translates domain names (google.com) to IP addresses.

Packet switching = postal service. Imagine sending a large letter by cutting it into 10 postcards. Each postcard is mailed separately, possibly by different routes. At the destination, they're reassembled. If one gets delayed, only that one needs to be resent — not the entire letter. That's packet switching.

Network key concepts

Client-server model: Client (your browser) requests data. Server stores and responds with data. You are always the client when you browse the web.
HTTPS ≠ HTTP: HTTPS encrypts data in transit. Always use HTTPS (look for padlock) for banking, passwords and sensitive information.
IP ≠ URL: IP address = 172.217.25.46. URL = google.com.au. DNS translates URLs to IPs automatically.

Quick reference

| Term | Meaning |
|---|---|
| LAN | Local network (school) |
| WAN/Internet | Global network of networks |
| Router | Directs data between networks |
| IP address | Device's address |
| Packet | Small chunk of data |
| Wi-Fi | Wireless connection |

Worked example (Easy)

You type "www.vcaa.vic.edu.au" in your browser. Describe what happens step by step.

DNS lookup. Your device queries a DNS server to translate "www.vcaa.vic.edu.au" into an IP address.
Request sent. Your browser sends an HTTP/HTTPS request (packet) to the VCAA server's IP address.
Server responds. The VCAA server sends back packets containing the webpage data.
Packets assembled. Your browser reassembles the packets and renders the webpage.

Answer: DNS → HTTP request → server response → packet reassembly → webpage displayed.

Worked example (Hard)

Apply your understanding of networks and the internet to analyse a complex real-world scenario, demonstrating integration of key concepts.

Identify key concepts. Break down the scenario to identify which specific concepts from this topic are relevant and how they interact.
Apply knowledge systematically. Use precise terminology and frameworks from this topic to analyse each aspect of the scenario.
Evaluate and connect. Consider broader implications and connections to other topics you have studied.
Synthesise conclusion. Draw your analysis together into a coherent, evidence-based conclusion.

Answer: Analysis demonstrates integration of multiple concepts with specific terminology and systematic reasoning applied to a real-world context.

Common mistakes

Providing surface-level answers without depth Students state facts without explaining underlying mechanisms or reasoning. Fix: Always explain WHY and HOW, not just WHAT. Go beyond naming to explaining the mechanism or process.
Not using specific terminology Students use everyday language when subject-specific terms are expected and demonstrate understanding. Fix: Use precise subject vocabulary — this demonstrates understanding and earns marks in assessments. Build a glossary of key terms.

Connecting concepts — how this topic links to the bigger picture

Every topic you study exists within a larger network of connected ideas. Understanding these connections transforms isolated facts into integrated knowledge — the kind of understanding that enables you to solve new problems, not just recall memorised answers.

Experts in any field think in terms of conceptual frameworks — organised structures of related ideas. When a doctor sees a patient, they don't recall every fact from medical school; they activate a framework of connected concepts that narrows possibilities efficiently.

Building these frameworks requires active learning: asking how each new concept relates to what you already know, looking for patterns across topics, and practising applying knowledge to unfamiliar situations. The goal is not to memorise more facts but to build richer connections between facts. Practice questions that require application to new contexts are valuable because they force you to build the connections that define genuine understanding.

Practice questions

What is the role of a DNS server?
1. Stores web pages for users
2. Translates domain names to IP addresses
3. Encrypts internet traffic
4. Connects devices in a LAN
(1 marks)
Explain what packet switching is and give ONE advantage of this approach.
(2 marks)

Summary

Distinguish LAN, WAN and the Internet.
Explain how data packets travel across a network.
Describe the roles of IP addresses and protocols.