What is the difference between Luma Waveform & RGB Waveform?

Luma shows the levels of brightness from an input source

RGB Parade will monitor the level of Red, Green and Blue from an input source.

The Luma or Luminance Waveform is a great way to visualize the dynamic range of your image, allowing you to protect exposure of both your highlights and shadow detail. It’s particularly useful when shooting with a low contrast Log curve and works in perfect partnership with the AtomHDR engine to illustrate the highlight clipping point to allow you to correctly expose you image.

RGB Waveform will monitor the level of Red, Green and Blue from an input source. The RGB channels are displayed side by side. This can be used to check to white balance. Just point the camera at something white and the Red, Green and Blue levels should match if white balance is setup correctly on the camera