Well, to be honest it's a bit of a surprise to me too!
To start at the beginning each of the 'bulbs' is actually made up of three LED emitters, red, green and blue called a pixel. These are all connected in parallel in a string of maybe several hundred one end of which is connected to a bespoke controller.
Controllers are connected using regular LAN cables, switches, APs and a router, all these are on a separate network to our home network.
To synchronise lights to music each item or 'prop' is visualised using a program called XLights which is written by developers in Australia and the US, whilst this is free - please be courteous and make a donation.
The music is imported along a timeline, all the props are laid out in horizontal rows below the timeline with a window to see the effects you've selected on the relevant props. Sounds easy? It can take 30-50 hours of work to sequence one song.....
When I set up the first show in 2016 I had to import all the controllers, pixels etc from the US and China which was time-consuming, costly and I kept getting hit with customs and VAT duty. Now, however, there is one particular company in the UK who have taken up the challenge to help newcomers get started, supplying everything you need from one source. Contact the team at Build A Light Show who are very knowledeable and helpful - they will get you started!
Other pixel controllers and DMX equipment is available from SmartShow Lighting they have a very unique range of products and are very hands-on.
I have used both these companies to source equipment and can recommend them personally.