2021 Highlander by Toyota

I am wondering about my new Vehicle. I actually didn't know I bought a Hybrid. I just needed a reliable SUV like now. But after driving it with my hearing aid in my head I noticed the engine shut off. The red light turned green and I stepped on the pedal and it started up and went forward instantly. I didn't hear a starter motor solenoid kick in and a 12 volt starter grind? Therefore it lead me to believe a 350 or 400 volt battery that started the ICE portion of the vehicle. It started fast and took off forward just as fast. I worried about the oil settling in crankcase and then being full power instantly. The other thing is most ICE engines used a 12 volt solenoid and a pinion gear to engage flywheel. Now after thousands of starting an engine it would tend to wear out flywheel teeth and pinion gears or anything else in that area.
So does anyone know how the engine starts after shutting dow at a red light. Toyota dealer wouldn't tell me what is going on and I can believe that. Either way it is quiet and fast. I had or maybe still have a Onan generator without a starter motor and all I used to do is lift switch up to start and generator portion started engine and it produced AC and when I flipped switch down it was off. Motor / Generator. But this Highlander is not a briggs engine and I think Prius said something like it had a 300 volt starter motor alternator system yes?
I have to find 12 volt battery and install more radios also maybe even add spare AGM battery so I always have a full vehicle battery and use AGM for computers, amateur radio and CB radios. oh , and coolers. If I see a tiny 12 volt battery then it starts via HV pack but if it has a 500 AH battery it is a 12 volt starter? Am I correct?