Can anyone explain what a power tube does inside an amplifier, eg kt88.

I've asked this question directly to humans and haven't had good answers. I don't think many people really do know. Google reference is not good on this point for some reason. YouTube doesnt offer an explanation of what happens inside a tube that I could find without getting odd vids scarily technical and not helpful.

And then there's this amazing forum which offers incredibly smart people willing to offer their knowledge and be very helpful.

So this is my last hope. 

@tonydennison 

Chat GBT did a great job above. And your comment asking how it actually controls the valve activity is very key.

Also there was a document above from @tablejockey that looks very promising.

Ultimately the end answer, is likely very simple, amidst all the complicated fog.

When you ask a child, even in adult, how something works, like how things work when you turn on a sink faucet you'll get a good answer. But if you start going into the actual inner workings of a faucet, the child quickly gets very frustrated. Human nature is a challenge.

Oh my God, the document above is 760 pages long.

It looks pretty damn awesome and it has pictures.  I wonder if it was ever translated into another language.  Fortunately I only can read English and how lucky I am this document is in English. I failed German when I was in high school. What an awful experience that was. 

Why is it necessary to have eight Power tubes on a mono block amp? Assuming its 300 watts, does this mean each tube is incrementally amplifying the total watt availability? Why not just do a few tubes, or would that means less watts available?

That's a lot of vacuum space for electrons to flow through going through so many tubes so quickly. I recall seeing one amplifier with a single tube about eight times the size of a kt88.

So is each tube individually responsible for incrementally amplifying signal?? I believe all eight tubes would be on the same circuit.

Just like a Christmas tree lighting system?