Look up Schedule times

Hello, I understand this pass is valid for trains in the "JR group" I'm having trouble finding which trains are part of this group. I found on another pass site its HIKARI, SAKURA, KODAMA, and TSUBAME. I found different ones on a few others. When I search train schedules on google maps I find a bunch of other trains running on the same track. Some say they are JR but most are not. Even between major cities I hardly find exclusively JR trains

I'm very confused where to look for a schedule of all the trains that are included in this pass. If I'm paying for the pass I want to use it as much as possible of course. Thank-you!