[dwaite]

Matter is a consortium effort by IoT vendors and enablers (Amazon, Apple, Google, Legrand, Silicon Labs to name a few interesting members) to consolidate (and hopefully commoditize) the space.

It is IPv6-based and standardized devices need to be able to operate without internet access. Devices can talk to one another directly, and it is possible to have multiple admins at once, e.g. I could have Siri and Alexa both understand the same light switch.

It is similar to GATT in Bluetooth; a certain level of composability of hardware devices offering sets of functionalities in the way of attributes and commands. - say for example, a smart speaker which can function as a two-way intercom and also has a humidity sensor and temperature sensor.

The spec defines Wifi networks but also networks using Thread, a low power mesh network which is IPv6 based, using 6LoWPAN and 802.15.4 wireless (so, a sibling of sorts to Zigbee).

Thread with Matter allow for both always-powered devices and "sleepy" battery-operated devices, which leverage those always-powered devices as routers in the mesh.

I haven't looked into that part yet, but you can also have higher bandwidth services over Wifi such as cameras and streaming. Amazon for example seems to be pushing for casting-style functionality to be standardized there (to compete against Airplay and Chromecast.)