I'm relatively new to the field of signal processing and might be a bit confused about terminology here. I'm trying to understand what determines whether I deal with a root-power or simple power quantity and how that relates to the RMS value of the signal.
I understand that the RMS of a signal is proportional to the signal's power. At the same time, this answer seems to heavily imply that RMS is equal to the root mean power (take sqrt on both sides of last equation). However, when looking at the wikipedia article on the calculation of decibels, they make it sound like whether I'm dealing with a power or root power is a property of the underlying signal, not the RMS value at all:
"As sound pressure is a root-power quantity, the appropriate version of the unit definition is used"
This leaves me confused. How do I determine whether I'm dealing with a power or root-power quantity, and what is their relation to RMS?