In DMX, a channel refers to a single control parameter that can be adjusted to control a specific aspect of a lighting fixture, such as its colour, intensity, or position.
DMX is a standard protocol used in the entertainment industry to control lighting and other effects. It allows multiple devices to be connected in a chain, with each device receiving a unique DMX address.
An example of DMX channels would be, if you were to have a RGB LED fixture, it would have three channels; one for red, one for green and one for blue. By sending DMX data to these channels, the colour of the LED fixture can be adjusted and mixed to your requirements.