DMX512 or DMX ("Digital Multiplex") controllers are required if you want to use LED pixels or RGB (W) LEDs over the standard DMX protocol.
You will need different DMX controllers for LED pixels or RGB (W) LEDs.
DMX controller for LED pixels with these controllers you can control LED pixels. The controller converts the DMX signals into control signals used by the chip of the LED pixel (e.g. WS2811).
DMX controllers for RGB (W) LEDs with these controllers allow you to control RGB (W) LEDs. The controller converts the DMX signals so that they can control the respective color (R, G, B (W)).