Hub is a term that’s used commonly for different things, resulting in confusion for many of our clients. Here’s a quick way to look at it:
An Aqara hub can be described as a “router” that broadcasts a wireless network called “Zigbee”, much like a normal router broadcasts your wifi. They are the networking type of hub – that is, your other smart devices connect to it wirelessly to transmit data and commands.
We have an article on how Aqara wireless networks and Zigbee works.
An Apple Home Hub is more of a “server” than a “router”. As long as you have one unit of an Apple Home Hub at home, that’s enough for you to gain access to Apple HomeKit’s extra features, such as remote offsite controls, HomeKit Secure Video, and more. The Apple Home Hub is processing data and commands with its own hardware.
Sidenote: some Apple Home Hubs also act as Bluetooth and Thread “routers”, so this further complicates matters. But, in the scope of most of our products, they do not work as routers.
A Google Home Hub is simply a smart speaker or screen that’s marketed as a centre of your smart home – that is – in terms of interaction. It’s a hub you can speak to to ask for the weather, or to turn off a light, or to see a video feed from a camera. Google Hubs do not work as routers nor as servers (their processing is literally done on a cloud server).