The Matter standard is a universal communication system that uses a Thread network to connect Internet of Things or IoT devices. Matter and Thread enable Internet of Things devices under multiple brands to be controlled with just one app or one platform. Most recently, this feature will be built directly into Android 15.
Based on the shared screenshot image, the connected Internet of Things device on the Android 15 phone allows users to activate Thread mode in order for the device to appear in this universal network. This means that users will be able to use an application such as Google Home on the phone to control various other devices. This feature is seen to be available in Settings > Connected devices > Connection preferences > Thread.
At the moment it is still unclear, what products can use the Thread setting in Android 15. Matter and Thread are still new, Samsung SmartThings, Apple Home and Google Home have already started to support it to make it easier for all users.