A:Answer The hub is what connects the lightbulbs to your WiFi or internet via Ethernet cable. It is needed to be able to have your phone or a smart voice, i.e. Alexa or google, control the bulbs.
Both lightbulbs need to be within the reach of the hub, about 40 ft, so they would both need to be in the same home.
There are version where the hub is not required and those would work in different homes