Quote from: RedApronPark on Today at 07:34:01 PM

Hi, I'm pretty new to crypto, and am trying to understand some of the technical concepts.

I think I get the concept of how miners run ASICs to find a PoW number that when SHA256 function is applied to the whole block with that number, it results in a working hash to make a valid block.

But they also need to validate each of the transactions within the block, right? And this requires checking the entire history of each of the included users' past transactions to verify that they have enough BTC to make a payment? For up to 2400 transactions per block, that seems very time consuming?

Am I misunderstanding how it works?

I tried to scan various FAQs and videos, but haven't found the answer to this question.

Thanks!

I'm not a miner, but as far as I know full nodes maintain so called UTXOs set which encompasses all UTXOs that are currently available in blockchain. Checking this set miners validate that UTXOs included into given transaction exist and are unspent.