For hardware, there are 4 types of devices that come in two pairs. You have bridges and routers, which connect two networks together. A bridge passes everything it get from one network to the other, blindly. A router is the smart version, as it only passes packets that go to the other network. Then you have (sort of in parallel) hubs and switches, Hubs send all packets to all ports. Switches pass packets only to the port they address. Switches can be cascaded, hubs can't.
[Pedant]
Not quite.
These days a network bridge is, at it's core, a software switch.* It takes packets in on its interfaces and sends them out only on the interfaces they're intended for.
A router does more than "only passes packets that go to the other network" it also modifies those packets so that responses come back to the router from the remote side. And modifies those back to the originator. Depending on settingss it can also block some or all traffic in one or both directions.
Routers and bridges also operate at different levels in the network stack. Bridges don't care about things like IP addresses and work without them. Routers do care and don't work without IP (or their equivalent) addresses.
Oh, and yes, network hubs can be cascaded but you very quickly end up with a network flooded with packets/frames and/or a failure in collision detection. Switches were developed to replace hubs for just this reason.
[/pedant]
*: at least in the context of creating/using a bridge on a Pi.
Statistics: Posted by thagrol — Wed Nov 05, 2025 12:58 am