How to understand blockchain?

Question

blockchain

Greetings. Interesting blockchain. Not only in cryptocurrencies, but in general - Web3.0, metaverses, NFT...
Naturally, I started to google. I realized that the blockchain is a chain of blocks (although this is obvious). All copies of this chain are stored on different computers. And blah blah blah, what are its advantages, what happens if someone changes the combination, etc.
Only here is more about it and what is under the hood - there is little information. And if there is, it seems to be different on different resources, and I didn’t manage to understand anything.

I have decided to seriously take up this whole movement and I want to know in detail about it.
Therefore, I want to ask those who know how the blockchain actually works.

Yes, maybe I googled badly and "here you are such a moron, go first learn to google, you won't get shit, etc., etc." .

Answer 1

The only thing that is important and that it makes sense to understand
is the consensus that allows the usual stupid blockchain (serial data chain) to be made provably non-rewritable, without the presence of a central trusted
i.e. literally everything else follows from the possibility of the existence of such a chain, such an algorithm, with the help of which a group of people who do not trust, who are financially interested in deceiving each other, can save data about their actions.
Starting from here, a cryptocurrency has been created (and not just one, but only bitcoin makes sense, why - below), in which, with the help of the blockchain and a reliable PoW consensus, a 'granary book' was created where transactions are literally recorded 'who transferred how many coins to whom' and everyone can trust these records, subject to consensus constraints (in the case of PoW, this is a 50% + 1 attack and the ability to pick up such a number of confirmations from circulating amounts that this attack can be neglected)
Of course, it doesn’t have to be limited to this, there are a huge number of tasks for which the ability to work without a trust center can be invented, and they were invented, although there are very few useful ones in practice from the whole variety (I won’t even list anything offhand except the actual function of money and the collective management based on multi-signatures, .. well, maybe even voting).
Since the very concept of independence from the center is difficult for the vast majority of the population to understand, this is used to throw dust in the eyes of the majority.
First, cryptocurrencies were created, both copying bitcoin and implementation from scratch with unusual functionality and concept, experiments with alternative consensuses and other things that showed thatConsensus alone is not enough to ensure the reliable functioning of the system , we also need such things as a high-quality initial distribution of value (blockchain coins, if roughly) and the presence of independent developers, more than one team, competent management and the will of participants to keep the system afloat. The requirement about developers is very philosophical and there are a lot of examples when, regardless of the consensus, the main developers, the owners of the main volume of values, were related / co-dependent, and were able to destroy a useful project (for example, what happened to bitshares, if that showed how vulnerable the PoS consensus is) .
Then, realizing that the majority of technical and philosophical concepts don’t care, literally, the developers began to create projects on already working blockchains (on which ethereum rose), the whole meaning of which ultimately began to come down to the icon, name and exchange, which agreed to list this slag on the site (one of the earnings of exchanges is to take a decent reward for this).
A logical continuation of the development of the concept of this trio, a contract (algorithm) appears on the blockchain - NFT, which actually represents it - an icon (picture), a name and an exchange (the contract allows you to trade and assign and distribute a commission for trading), which has been successfully implemented on several blockchains.
All the near-philosophical tinsel stuffed with neophytes is complete nonsense that does not stand up to the simplest logical analysis. The main goal of the bulk of crypto projects in cryptoeconomics is to take money from the population. The main way to make money on NFT is either commission fees (this is done by centralized platforms that promote NFT projects of authors, i.e. marketing) or trading simulation when the author buys his own goods from himself - showing fake interestthem (nothing new has been invented and this has been done for a long time even before smart contracts, both exchanges and the authors of crypto projects themselves). And of course, money laundering, literally - whitewashing gray finance, when value is generated from nothing, this is just an excuse to show that the money was received from the sale of these works of art, which has long been used in the big world of money, .. nothing new.
ps why only bitcoin? because only in it the distribution of wealth is noticeably even ( Gini index ), only its consensus is backed up by huge financial investments in mining equipment (a very expensive attack) and a huge community of independent developers(although there are a lot of places for the weakness of the project, but compared to others, bitcoin looks like the most secure).
The rest of the projects are created not to bring anything useful to the world, but to raise money, or as a fundraiser for development (ICO or commission in the blockchain), and when the consensus is based literally on the amount of money (pure PoS), then the very fact that the main money of the project is concentrated with someone alone (the creator or an oligopoly of investors, as is done in EOS, or rather dPoS projects) completely nullifies any protection.
pps I was interested in the only alternative consensus - proof of identity (now it is idena.io - about 2k-3k nodes, 7k..14k 'miners' and the number is growing ~ 10%per month, for a young weak project this is a miracle in cryptoeconomics), the main trouble of the majority of non-PoW is the possibility of an attack by the number of nodes or money, but here one identity = one person (well, ok, two is the norm), this guarantees consensus, but the danger of collecting farming slaves to attack the project is complicated by the low cost of the coin, i.e. paradoxical as it may seem, as long as the income of miners here is low, the consensus will be reliable
i.e. it is safe to create blockchain-based projects with PoI consensus, but it is already dangerous to make a project financially dependent on its coin.
heh, it would be necessary to issue this in the form of an article on habr and send people there

Answer 2

what are its advantages

Nothing. Just a trendy hype theme. Just like clouds. At first, they tried to shove the unpushed as always, someone raised the dough, someone went bankrupt, after the hype passed and the scope became clear - they sit quietly and do not buzz, because the scope turned out to be very narrow and very specific ...

Answer 3

Did you ask? So that's great. But if you decide to "take on this whole movement" seriously (however, I still don't understand why the word "movement" is here, but oh well), then you need to learn not from "different resources", videos and websites, on which one a student, after listening to a lecture with the air of a connoisseur, sets out what he understood, but from books. Which are at least understandable by whom written, and at least somehow reviewed. Here, study them. And then you will understand exactly what it is and what is "under the hood"
You can start, for example, from here:
https://www.amazon.com/Blockchain-Dummies-Computer...
Then read:
https:// www.amazon.com/Mastering-Blockchain-distri...
Well, after that, you yourself will figure out where to dig further.
Good luck.

Answer 4

Kamrad, I’ll help you in any way I can: 1) Not only everyone can immediately get into the topic of blockchain, 2) There is some kind of cult book on this topic, but I don’t remember its name)) (maybe someone will tell you in the comments) - and there in detail the bitcoin device is considered, it is chewed right on the fingers, it is in Russian, in the Deja Vu format. In general, all crypto experts hang out on bitcointalk (Google will tell you) - there is a Russian section there.

Answer 5

full of information
https://coursehunter.net/blockchain

Answer 6

Not only application in cryptocurrency, but also in general - Web3.0, metaverses, NFT...

You don't need to understand anything - it's a scam. Nothing new, just other "tools" to cheat gullible users who want to understand the blockchain.