There are many Smart home devices and most are incompatible to each other. This is expected to change by the end of 2020.
Apple, Google, Amazon, Ikea, Somfy and many others have joined forces to work on a common standard and to make the offered devices freely combinable. A very good and praiseworthy approach. Because currently even the professional user has to check again and again which standard a device works with and whether it can be combined with other devices.
The protocol used is called Connected Home over IP and is therefore based on the normal IP protocol. In addition, it should be made available to everyone without having to pay license fees. Whether it is backwards compatible to existing devices remains to be seen – currently the website says that one is only planning for the future.