Z-Wave is a mesh networking technology commonly used for home automation that allows many different brands of products to interoperate with each other very easily. However, it is a patented proprietary protocol that requires a licensed Z-Wave chip, which are not generally available to the hobbyist at affordable rates.
To communicate, Z-Wave devices must be joined to the same Z-Wave mesh network. That means you need to have a primary controller somewhere, at least for the purpose of pairing. The primary controller does not have to be present when the scene executes; and the primary controller does not necessarily have to be connected to the Internet (but that's not very IoT.)
Some commercial Z-Wave switches are "scene capable", meaning you can install and use them as a typical wall switch, and they can trigger behavior directly in other Z-wave devices without needing to send a message to the primary controller. Usually this is fairly primitive, meaning you can have one light switch turn on several other light switches, but nothing more sophisticated.