Networking: LAN, WAN, and How They Connect
Distinguish local from wide area networks, understand how a LAN moves data, and see how the two connect to reach the internet.
By the end of this lesson you can
- Distinguish a LAN from a WAN
- Explain how devices on a LAN communicate
- Describe the equipment connecting a LAN to the internet
- Compare wired and wireless connections and choose appropriately
Lesson Notes
Read through the key concepts before you try the challenge.
Two scales of network
Lakeside Medical Associates operates two locations.
Each office has its own local network of workstations, printers, and wireless. The two offices need to share systems, and both need the internet. Three different kinds of connection are involved, and calling all of them 'the network' makes every conversation about them confusing.
Your task: Distinguish the scales of network so you can describe where a problem or a requirement sits.
A LAN is a local area network — the devices in one location, connected to each other, typically owned and managed by the organization. A WAN is a wide area network spanning locations, usually over infrastructure someone else owns. The internet is the largest WAN there is.
| Property | LAN | WAN |
|---|---|---|
| Covers | One building or site | Cities, countries, or globally |
| Owned by | The organization | Telecom carriers and service providers |
| Speed | 1 Gbps and upward, typically | Limited by the purchased connection |
| Latency | Under a millisecond | Tens of milliseconds or more |
| Cost | Equipment purchase | Recurring service charges |
| Example | The workstations in one office | The link between the two offices |
Inside a LAN, each device has an IP address. A switch forwards traffic to the intended recipient rather than broadcasting it to everyone, which is what makes a switched network both fast and reasonably private. The router is the boundary — it connects the LAN to everything beyond it and decides what may cross.
| Consideration | Wired (Ethernet) | Wireless (Wi-Fi) |
|---|---|---|
| Speed | Consistently fast | Varies with distance and interference |
| Reliability | Very high | Subject to interference and congestion |
| Security | Requires physical access | Reachable from outside the building |
| Mobility | None | The entire point |
| Best for | Workstations, printers, servers | Laptops, tablets, phones, visitors |
Two Lakeside offices are connected over the internet using a VPN. What does the VPN provide?
Challenge
Apply what you've learned in this lesson.
Map a real network and reason about its structure.
- Draw the network of a place you know. Show the modem, router, switch, access points, and every connected device, and label which are wired and which wireless.
- Mark the boundary between the LAN and the WAN on your diagram, and explain what crosses it.
- For each device, state whether wired or wireless is the better choice and why.
- Explain in three sentences why the two Lakeside offices need a VPN rather than simply connecting over the internet.
Finished this lesson?
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