In this lesson, you will learn how computer networks enable us to share data.
🎯 Learning objectives
| Bronze | Define key networking terms including network, node, LAN & protocol. |
| Silver | Explain the role of protocols in network communication. |
| Gold | Describe how networks use packets to send & receive data. |
💡 Big idea
In the 1940s, when the US military had harder problems to solve, they built bigger computers. But computer pioneer Grace Hopper had a different idea:
“When my daddy had a stump on the farm that one ox couldn’t pull out, he didn’t wait to grow a bigger ox. He would chain two together to pull out the stump. If it didn’t move, add another ox until it did. We don’t need bigger computers. We just need to get them to pull together.”
What does this mean?
Grace Hopper, USN
1906-1992
What is a network?
| Bronze | Define key networking terms including network, node, LAN & protocol. |
Video summary: optional read
Networks are all around us. Roads and power lines are types of networks that help us travel and bring electricity to our homes. But one of the most important networks today is the computer network, which lets devices like laptops, phones, and printers connect and share information. Even using Wi-Fi at home is part of a network.
In a small place like an office or school, a group of connected devices is called a Local Area Network (LAN). Each device is called a node, and they share information through connections. To make sure everything works properly, computers follow special rules called protocols. These rules help data travel safely and reach the right device.
When many networks connect together, they form the internet—a global network of networks. Your computer becomes part of this when you go online, letting you visit websites and send messages to people all over the world. Whether you’re online or offline, networks are always helping things move and connect.
What are protocols?
| Silver | Explain the role of protocols in network communication. |
- It is important that computers made in different countries and by different manufacturers can communicate with each other.
- This is achieved using protocols. These are internationally agreed upon sets of rules about how things should work.
- Networks are governed by two main protocols which work together in tandem. These are called TCP/IP (Transmission Control Protocol/Internet Protocol).
Task: Note down definitions of the key terms from this lesson in the Glossary [Google Doc]
Packet switching
| Gold | Describe how networks use packets to send & receive data. |
Before a file can be sent over the internet or a network, it gets broken into smaller pieces called packets. Each packet carries part of the file, like a puzzle piece. It also includes the IP address of where it needs to go, like the address on an envelope.
The TCP/IP protocol is a set of rules that makes sure all the packets are sent the right way. These two protocols work together, but each has a distinct role:
- TCP checks that all the packets arrive and puts them back in the right order.
- IP helps each packet find the right destination.
Together, they make sure the file gets to the right place safely and correctly.
Task: Map packet switching as a flowchart. You can do this on paper or digitally:
- Print a copy and fill it in by hand. [Google Doc]
- Create a digital copy [diagrams.net]
Advantages of packet switching
The animation below shows a visual metaphor of one of the advantages of packet switching.
Separating large files into packets means, like cars, they can merge at junctions and keep moving at a steady speed. This process allows lots of packets from lots of devices to travel down the same cables without causing a traffic jam. The network keeps running quickly and efficiently because it’s handling many small packets rather than getting stuck with one big file transfer. Other advantages include:
- More reliable: If one packet gets lost, only that packet is re-sent – not the whole file.
- Can take different routes: Packets can find the quickest path through the network, avoiding busy or broken parts.
- Better for the internet: It works well with all kinds of data, from websites to video calls, and keeps everything moving.
Find out more
Prep task: network hardware
Next lesson will focus on different types of network hardware, including routers, switches and hubs. Research these terms online and come prepared with definitions.