From/To RTDX vs Digital Input/Output for TI C2000

Hi! Beginners question here :)

What is the difference between From/To RTDX and Digital Input/Output blocks for TI C2000 C28x3x card? Digital Input/Output are preaty much straightforward to understand; similarly ADC block.

But I'm having trouble understanding when and why to use From/To RTDX blocks! In the help, it says: "Input channels transfer data from the host to the target." I suppose host is a PC and target DSP. But eventually, I would like to download the program to DSP and run without PC. Are From/To RTDX used like monitoring (scope) and control (set values) type of inputs/outputs? Or am I getting this all wrong?

Please help. Thanks.