Beginner prob stupid question

One part of my project is a perimeter along ceiling with 5 1/2 strings total
I have power injection points at every 16 feet what I dont understand is the data wire, do I treat it like 5 sep channels using a data wire for each strip or daisey chain the strips together same data chanel and just inject the 12 volts at every point needed?

Using dig-quad and ws2815 strips

Than you

Power for addressable LEDs is all parallel, the strip has a V+ side and a Ground side which can each be thought of as “one wire” with the LEDs attached along the strip. Your power injection points make up for voltage drops from that built in wire.

Data on the strip is serial or “Daisy Chained”, each LED has a Data In and Data Out. On the strip, the main Data In (1st LED) connects to your ESP board then the Data Out of LED 1 connects to Data In of LED 2. This continues with rest of the LEDs until you get to the end of the strip (which will have a Data Out).

How you deal with multiple strips is up to you, if you want you can continue the data chain tying the Data Out of one strip to the Data In of the next. That will use one GPIO pin on your ESP board. Alternatively you can run a separate data line for each strip using 5 GPIOs on the ESP.

WLED lets you treat them both as one long strip in the software. The difference will be in the length of the data runs. The end of one strip is usually fairly close to the start of the next so the Data Out to Data In distance is short. Running multiple data lines back to the controller may create overly long runs that are prone to flickering.

The only other thing to watch would be memory limitations (due to the total # of LEDs) in the dig-quad depending on if it is ESP8266 based. ESP32 devices should be fine.