GCSE · Computer Science · AQA · Spec 8525

Local Area Network (LAN)

Your school's Wi-Fi covers the whole building, but it must stop somewhere. Where does 'our network' end and someone else's begin?

Computer Science · Structure

Inside a school LAN

Tap any part to see its job. Then find the exact spot where the school's own kit stops.

One school building — the LAN, all equipment owned by the schoolWi-FiWi-FiLeased link

Tap any part of the diagram to see what it does.

Networks · LAN or WAN?

LAN or WAN? You decide

Pick a network, then pick the box it belongs in. Commit first, then read the reason.

Still to sort

LAN (0)

Small area, such as one building or site. The organisation owns its equipment.

Where the line is: Wired or wireless, a few devices or hundreds: none of that matters. Small area plus owned equipment does.

WAN (0)

Large area. The links are leased from a provider.

Where the line is: A WAN can join up several LANs, but each LAN stays a LAN.

5 of 5 still to sort.

Two questions settle it: how big is the area, and who owns the links?

Networks · Performance

?

Reason it through

Why is a LAN usually faster, with fewer errors, than a WAN?

Link 1 of 4

First link · your turn

Start with distance. How far does data have to travel across a LAN?

2
Locked — reveal the link above first
3
Locked — reveal the link above first
4
Locked — reveal the link above first

Networks · What makes a LAN?

Which of these sounds like you?

A school runs its own switches and Wi-Fi access points across one building. A link leased from a provider carries the school's data out to the Internet.

Which idea is closest to what you really think makes the school's own network a LAN?
How sure are you?

Networks · Advantages and disadvantages

Should a small business build a LAN?

The claim

A small business should connect its computers in a LAN.

Place each piece of evidence to load the balance. Mark the strong ones — they count double.

  1. Staff can share files and printers across the network.

    Evidence 1: does it support or challenge the claim?

  2. All the computers can share one internet connection.

    Evidence 2: does it support or challenge the claim?

  3. Backups and user accounts can be managed centrally.

    Evidence 3: does it support or challenge the claim?

  4. Staff can log on from any computer on the network.

    Evidence 4: does it support or challenge the claim?

  5. The switch, cabling and access points cost money, and the network needs managing.

    Evidence 5: does it support or challenge the claim?

  6. Malware, or an intruder who gets onto one device, may be able to spread to the others.

    Evidence 6: does it support or challenge the claim?

  7. If the switch or server fails, many users can lose access at once.

    Evidence 7: does it support or challenge the claim?

WHAT YOU'VE LEARNED

A quick recap of today's lesson.

What makes a network a LAN, and where it stops being yours

What you need to know

  • A network is a group of devices joined by links so they can share data and resources, such as printers.
  • A LAN (local area network) covers a small geographical area, such as one building or site.
  • The organisation that uses a LAN owns, installs and controls its cabling and equipment itself.
  • Have a goFinish the sentence: a LAN is identified by its small ______ and by who ______ the equipment.

    Area (geographical area) and owns.

    Those two features define a LAN. How many computers it has, or whether it uses cables, does not.

  • Devices join a LAN by wired links (copper or fibre cables) or wireless links (Wi-Fi). Both count.
  • A switch connects the wired devices on a LAN. A wireless access point lets Wi-Fi devices join it.
  • Have a goYou're the network manager. A games console is plugged in with a cable and a phone is on Wi-Fi. Which piece of kit does each one connect through?

    The console connects through the switch, and the phone through the wireless access point.

    A switch is where wired devices plug in. A wireless access point is where Wi-Fi devices join.

  • A WAN (wide area network) covers a large area using links leased from providers. The Internet is the largest WAN.
  • Have a goYour classmate announces, very confidently, 'The Internet is just a really, really big LAN.' What's the quick correction?

    It's not a LAN. It's a WAN, the largest one.

    A LAN covers a small area, but the Internet's area is as large as it gets, so it is a WAN.

  • Because a LAN is small and under the organisation's control, it is usually faster, with fewer transmission errors, than a WAN.
  • LAN advantages: sharing files and printers, sharing one internet connection, central backup and management, logging on from any computer.
  • LAN disadvantages: hardware and management cost, malware or intruders spreading across devices, and a failed switch or server stopping many users.

The big picture

A LAN (local area network) covers a small geographical area, such as one building, and the organisation owns the equipment. It can be wired or wireless, with a switch for wired devices and a wireless access point for Wi-Fi devices. A WAN covers a large area using links leased from providers, and the Internet is the largest. A LAN is usually faster with fewer errors, and it brings advantages (sharing, central management) and disadvantages (cost, spreading malware, single points of failure).

Key points

1A LAN covers a small geographical area, and the organisation owns and controls its equipment.
2A LAN can be wired, wireless or both. Neither cables nor the number of computers decides it.
3A WAN covers a large area using leased links, and the Internet is the largest WAN.
4A LAN is usually faster with fewer errors than a WAN, thanks to short distances and owned equipment.
5Weigh LAN advantages (sharing, central management) against disadvantages (cost, malware, failures) to reach a judgement.

Worked example

Problem

A library has 12 computers and 2 printers in one building. They are joined by cables to a switch, and a wireless access point lets visitors' phones join. The library owns all the cabling and equipment. Explain why this is a LAN and not a WAN.

⚠ Watch out

Saying a network is a LAN 'because it uses cables' or 'because it only has a few computers'. Wi-Fi networks are LANs too, and size is measured by area covered and who owns the equipment, not by device count.

🧠

Memory hook

Think of your own front door. Everything inside, you own and control: that's a LAN. The road beyond it is shared and belongs to somebody else: that's the WAN side.

✓

Check yourself

A practice owns a switch, 5 cabled computers and a wireless access point in one building. Is its own network a LAN or a WAN? Give the two facts that decide it.

Flashcards

(12)
What is a computer network?
A group of devices joined by links so they can share data and resources, such as printers.
What does LAN stand for, and what is one?
Local area network: a network covering a small geographical area, such as one building or site.
What two things identify a LAN?
Its small geographical area, and that the organisation owns and controls the equipment.
Does a LAN have to be wired?
No. A LAN can be wired, wireless or both. Cables do not define it.
Does the number of computers decide whether a network is a LAN?
No. Even a LAN with hundreds of devices is a LAN if it covers a small area on equipment the organisation owns.
What does a switch do on a LAN?
It is the central box that wired devices plug into, joining them together as one network.
What does a wireless access point do?
It lets Wi-Fi devices join the network.
What does WAN stand for, and what is one?
Wide area network: a network covering a large geographical area, using links leased from providers.
What is the largest WAN?
The Internet.
Why is a LAN usually faster with fewer errors than a WAN?
It covers a small area and uses equipment the organisation controls. Data travels a shorter distance.
Give two advantages of a LAN.
Sharing files and printers, and sharing one internet connection. Central backup and logging on from any computer also count.
Give two disadvantages of a LAN.
Hardware and management cost, malware or intruders spreading across devices, and a failed switch or server stopping many users.

Tap any card to flip it, or use Study as deck to go through them one at a time. In the full lesson these run as a spaced-repetition deck — you rate each card Hard, Good or Easy and the tricky ones keep coming back until they stick.

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