Is this Zigbee based? If so does it need a Zigbee to Internet gateway to function?
Yes, it is Zigbee based, it works under the same standar (802.15.4 radio frequency). For being connected to internet it needs a module that bridges the device with the internet.
It's based on the same standard as Zigbee (802.15.4), but uses an open communication protocol that simplifies communication with Actions (Like turning on a light 75%) and Events (Like "Presence detected").
For communicating to the Internet we use a "hub", like a Raspberry pi, which has a web-based user interface and a REST API.