Matter is the common application language
Matter defines how supported device types can be commissioned and controlled across compatible ecosystems. A Matter logo does not identify the radio by itself; Matter can run over Wi-Fi, Ethernet, or Thread.
Thread is an IP mesh network
Thread is a low-power IPv6 mesh used by devices such as sensors and locks. Thread devices need a compatible border router to connect the Thread mesh with the home's other IP networks.
Zigbee needs a coordinator or hub
Zigbee is a separate low-power mesh technology. Its devices generally connect through a compatible hub or coordinator, which may then expose selected devices to other ecosystems.
Controller and border router are different roles
A Matter controller commissions and manages Matter devices. A Thread border router moves traffic between Thread and the rest of the network. One physical product may perform both roles, but the roles are not interchangeable.
Plan the offline path
For locks, lights, and climate, keep physical controls and local entry available. Cloud accounts, remote access, and voice assistants should enhance essential controls rather than become the only path.