The data as it goes through your wifi or Ethernet adapters

it doesn't interrogate your router, it gets if from the computers network adapters

No smoke and mirrors.

Logs Netstat -e / Get-NetAdapterStatistics :)

Thanks for replies … so it only reports specifically about a single device?

What I mean is does the data usage figure shown, for example, on my desktop, also include any other device usage connected to the router (ethernet or wifi)?

It has no idea what router it has connected, nor other clients.

So no.

It is to the device running W10. 

Got it 😊

only the device you are on