Yup, and yup. Thanks to the internet and some good plumbing books, I figured that out. What I find even more interesting is that I have two sections of pipe in front of me. Both labeled as 3/4", and both from Charlotte Pipe. Yet one has a considerably larger ID, OD, and wall thickness than the other. One is CPVC and the other is PVC. The PVC is the larger.
CPVC: ID/.72, OD/.875, wall/.094
L copper ID .785/OD .875/ wall .045
PVC: ID/.828, OD/1.06, wall/.125