Traditionally, DMX512 was used to send up to 512 channels to dimmer packs in stage lighting applications. Each channel value (0..255) simply corresponded to the required intensity (0..100%) for the light(s) assigned to that channel. When other devices (such as moving heads) started using DMX512, the values were used for pan/tilt position and for gobo (pattern) selection, etc.

The point is that DMX512 is just a group of 8 bit values in a frame. The values can vary each frame (for dimming / flashing, etc) but don't have any inherent meaning by themselves. It's up to the sender (lighting console or sequencing software) and the receiver (dimmer, pixel controller, moving head) to use that data in some predefined way.

Feel free to ask more. That's how we all learn.