Inside a school, the corridor system directs people to the right room. The school gate connects the building to the outside world and finds the best route to any destination beyond it. A network switch is the corridor; a router is the gate — both essential, but operating at very different scales.
What is a network switch?
A network switch is a hardware device that connects multiple devices within the same local area network (LAN). It receives data packets from one connected device and forwards them directly to the intended recipient device — and only that device.
Imagine six computers all plugged into a switch. When Computer A sends a file to Computer D, the switch reads the MAC address (a unique hardware identifier) on the data packet and sends the data only to Computer D's port. Computers B, C, E, and F receive nothing. This targeted forwarding is what makes a switch more efficient than an older device called a hub, which broadcast data to every connected device indiscriminately.
Switches operate at Layer 2 (the data link layer) of the OSI network model — they work with MAC addresses, not IP addresses.
What is a router?
A router is a hardware device that connects different networks together and directs data between them. Its most common job in a home or school is to connect the local network (LAN) to the internet (WAN — Wide Area Network).
When you request a web page, the router:
- Receives the request from your device on the LAN.
- Reads the IP address of the destination (the web server).
- Selects the best route across the internet to reach that address.
- Forwards the packet toward its destination, which may pass through many further routers along the way.
Routers operate at Layer 3 (the network layer) — they work with IP addresses, not just MAC addresses.
How do switches and routers compare?
| Feature | Network Switch | Router |
|---|---|---|
| Connects | Devices within a LAN | Different networks (LAN to WAN / internet) |
| Address type used | MAC address | IP address |
| OSI layer | Layer 2 | Layer 3 |
| Sends data to | Only the specific destination port | The next hop toward the destination |
| Common location | Inside a school building or office | At the boundary between LAN and internet |
| Can assign IP addresses? | No | Yes (via DHCP) |
What is a MAC address and why does a switch use it?
A MAC address (Media Access Control address) is a unique 48-bit identifier burned into the network interface card (NIC) of every networked device at manufacture. No two devices in the world share the same MAC address (in theory).
Example MAC address: A4:5E:60:B2:1F:7C
A switch builds a MAC address table — a record of which MAC addresses are reachable via which of its physical ports. When a packet arrives, the switch looks up the destination MAC address and sends the packet only to the corresponding port.
What other network devices should I know at KS3?
| Device | What it does |
|---|---|
| Hub | Broadcasts data to all connected devices — inefficient and now largely obsolete |
| Switch | Forwards data only to the intended device — the standard LAN connection device |
| Router | Connects networks and routes packets between them |
| Access point (AP) | Provides wireless (Wi-Fi) connectivity — often built into home routers |
| Modem | Modulates and demodulates signals to connect to the ISP's physical line |
| Firewall | Monitors and filters network traffic for security |
In a typical school network, you would find: an internet connection → a router at the building boundary → switches on each floor → devices connected to those switches, with wireless access points providing Wi-Fi throughout.
What do exam questions about switches and routers ask?
KS3 and early GCSE questions commonly ask:
- "State the difference between a network switch and a router."
- "Explain why a switch is more efficient than a hub."
- "What address does a router use to forward data?"
- "Describe the role of the router in connecting a school LAN to the internet."
Always link your answer to the type of address each device uses (MAC for switches, IP for routers) and the scale at which each operates (within a LAN vs between networks).
Frequently asked questions
Is the box my broadband provider sent me a router or a switch?
It is almost certainly a home gateway that combines several devices: a router (connects your home LAN to the internet), a switch (so multiple wired devices can connect), a wireless access point (Wi-Fi), and often a modem (for the physical broadband connection). Consumer devices combine all of these for convenience; enterprise networks use separate, specialised hardware for each function.
Do routers always connect to the internet?
No. Routers connect any two different networks — for example, a large school might use routers internally to connect its science-block network to its administration-block network. Internet connectivity is one common use case, not the only one.
What is DHCP and which device handles it?
DHCP (Dynamic Host Configuration Protocol) is a service that automatically assigns IP addresses to devices when they join a network. In a home or school, the router typically runs the DHCP service, giving each device a unique IP address without any manual configuration.
Why does a switch not need an IP address to forward data?
A switch works at Layer 2 using MAC addresses, which are hardware-level identifiers that do not depend on IP. IP addresses exist at Layer 3 and are only needed when data must cross network boundaries — the job of a router, not a switch.
Preparing for a networks question in your computing assessment? Visit aitutors.me — Professor Turing will test your understanding of network hardware with tailored exam-style questions.