A HomeKit bridge is a special kind of accessory. It is not doing much itself, but it makes it possible to use accessories of a different technology. For instance Philips Hue lightbulbs do not ‘speak’ HomeKit themselves, they use ZigBee. The Philips Hue bridge makes all the Zigbee lightbulbs look like HomeKit lightbulbs, including their characteristics such as On/Off, dimming and color.
Thinka for KNX is a HomeKit bridge that opens up the world of KNX to HomeKit. Thinka translates KNX types and group addresses to HomeKit types and characteristics. Thinka connects to the KNX bus via twisted pair or IP Gateway and listen and writes to the bus. It hides the complexity of the KNX protocol and translates values and changes back and forth.
The Thinka for KNX bridge supports a large number of HomeKit accessories and has been certified by Apple to do so.