Modem, router, switch, access point: what each one does
In short: The modem connects you to your provider, the router connects networks and directs traffic, the switch connects devices inside a network, and the access point adds Wi-Fi. Home routers often combine all of these in one box.
The main devices
| Device | Job in one sentence | Everyday comparison |
|---|---|---|
| Modem / ONT | Connects your building to the internet provider's line (DSL, cable or fibre). | The front gate to the outside world |
| Router | Connects different networks and chooses where each packet goes. | A post office sorting letters between cities |
| Switch | Connects devices inside one network and sends data only to the right port. | A building's internal mail room |
| Access point | Lets devices join the network using Wi-Fi. | A wireless doorway into the building |
| Firewall | Allows or blocks traffic based on security rules. | A security guard checking IDs |
Why home is confusing
Your home "router" from the internet provider is usually several devices in one box: modem, router, switch (the LAN ports), access point (Wi-Fi), firewall and DHCP server. In offices these are separate devices so each can be bigger, faster and managed properly.
Switch vs hub
Old hubs copied every message to every port. Switches learn which device is on which port (using MAC addresses) and send data only where it needs to go. That's faster and more private, which is why hubs are no longer used.
Which device is the problem?
- Nobody can reach the internet, but local devices work → modem, router or provider.
- One area or floor is down → that area's switch or access point.
- Only Wi-Fi users are affected → the access point or wireless settings.
Real-world example: a small office with separate boxes
Imagine an accountancy office with ten staff. In the comms cupboard you find a fibre box (the ONT) from the internet provider, a router or firewall next to it, and a 24-port switch with cables running to every desk and printer. On the ceiling of each room there is a small white disc: an access point.
One morning, nobody upstairs can join Wi-Fi, but the desktop PCs with cables work fine and so does Wi-Fi downstairs. Using the job of each device, the problem narrows quickly: the internet and router are fine (cabled PCs work), so the fault is with the upstairs access point. Its light is off, and its cable had been knocked out of the switch.
Try this: find your home router and look at its back panel. Spot the port for the provider's line (the modem side), the LAN ports (the built-in switch) and the Wi-Fi light (the access point). You are looking at several devices in one box.
Key takeaways
- Modem = link to the provider; router = connects networks.
- Switch = connects devices inside a network; access point = Wi-Fi.
- Home routers combine many devices in one box.
- Knowing each job helps you find where a problem is.
Original content written by Mohamed Fayas for FM TecHub. © 2026 FM TecHub. You're welcome to share a link to this page; please don't copy the text elsewhere without permission.