Phone → cloud → controller
When you tap 'Christmas' in the app, your phone sends a message to the manufacturer's cloud server. The server pushes that command down to your control box over Wi-Fi. The box translates it into per-pixel commands for the LED strip.
It happens in well under a second on decent home Wi-Fi.
What runs locally
The control box stores its current scene and schedule on-device. If your Wi-Fi or the cloud goes down, lights keep running whatever they were last told to run. They just stop accepting new commands until connectivity returns.
Smart-home integrations
Alexa and Google Home use a routine: you say 'Christmas mode' and Alexa sends an API call to the manufacturer's cloud, which forwards it to your box. Same chain, different starting point.
Control4 and Nice Elan integrations talk directly to the controller over your local network — no cloud round-trip — which is why they feel instant on professional smart-home setups.
