Ok, so I'd say I have a very strong understanding of the fundamentals of Bitcoin, and the blockchain in general. I can explain pretty much (at a high level) the flow of almost every part of the ecosystem. << I say that not because I think I know even a fraction of what people on this forum do, but rather to give an honest assessment of where my question is coming from.

However, I do not understand what is happening at a technical, and I guess somewhat low-fundamental level, when a block is "added to the chain." I frequently hear people talk about, "Oh yeah, so after the miners mine a block, then they pack it with transactions, then boom, it's added to the chain. And it's secure because all the blocks require a lot of work to reverse." It seems most people are satisfied with that answer. Nothing wrong with that, it's just I'm looking for more.

I would greatly appreciate if someone (or multiple people.. the more the better) could explain what's actually going on there. What actually determines "We're done with this block, now let's add it to the chain." What is happening at a technical level when that block is added to the chain? What code is being run to facilitate this? Who has write access to the chain?


English is not my first language, so I apologize if I'm not articulating my questions accurately. There's just a knowledge void that's making me uncomfortable. I really want to understand everything about the process; every detail is meaningful to me.


Thanks in advance.