PRI: What Is A PRI?

I drew up a chart of info about PRIs.  Maybe it will be helpful to you as well.  ADDITION** I had to go edit my chart here.  My peer Jim S had to correct me and tell me had has got data over a PRI before.  So I stand corrected and now Im having to say that a PRI is not for voice only, but you can put data on it as well.  I modified my chart below.  I personally have not done that before.  Every time I have put in a PRI or used a PRI in any way, it has always been for voice only.  However, Jim is a pretty smart guy and he says he has done voice and data across a PRI before.  So, I have no reason not to believe him.  Thanks Jim.