When I had my first sleep study, I had an RDI of 63. I never heard the term AHI until recently. How do these terms differ?

I have had severe OSA since (I think) the 1990s. I had my Uvula removed some years after that. It was the "cure of the time", not! It is one of the life choices I regret. I have to say, with the continued updates to the masks and machinery, you should have no problems adjusting to the CPAP after a t...