The biggest problem in learning blockchain is that the industry's terminology is too "high-end", obscure and out of touch with reality. Without a particularly deep knowledge background, it is difficult to understand what an article is about, and it is also difficult to understand what a protocol or project is trying to do. I suffered a lot when studying blockchain, so I wanted to organize what I could understand into easy-to-understand language that ordinary people can understand:

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What is blockchain?

Blockchain is a distributed (decentralized), immutable database (ledger)

Speak human language!

Your childhood friend Erlu wants to borrow money from you. If you lend it to him, you may be afraid that he will default on the debt since he does nothing all day. If you don't lend it to him, after all, you two once dug out bird nests together when you were little, and now you often drink and brag together.

You're in a bit of a dilemma.

Erlu suggested asking the village brigade secretary to testify. You thought to yourself: The brigade secretary is your uncle. If you really don’t pay him back, will he still stand by me?

But what if blockchain technology is used?

Erlu shouted to the whole village through the village loudspeaker: Today I, Erlu, borrowed 10,000 yuan from Gousheng. You must pay it back before the end of the year. If you don’t, I’m a bastard. Please help me as a witness if I don’t pay you back.

Look at this scene, doesn’t it have a bit of blockchain flavor: Erlu shouted on the loud speaker (broadcast), and the whole village knew about the loan (distributed). Unless Erlu made everyone lose their memory, it would be impossible for him to deny it later (unalterable).

So you see: blockchain can not only change the world, but also restrain idiots.

Now the question arises again. Why should the old men and young wives in the village help you keep accounts and serve as witnesses? You have to give them some benefits. After all, you can't just rely on love to generate electricity.

good question!

Back to the scene where Erlu borrowed money from you, in order to reward the person who testified for you, you announced in the village that whoever helps me testify (keep the accounts) will be given a pancake baked by my mother.

But an unexpected problem arises. Because your mother's pancakes are so delicious, everyone is scrambling to keep accounts for you in order to get a big pancake reward. You see this is not a good idea. If you give each account-keeper a pancake, your own mother will be exhausted. So you add a rule: Let me give you a riddle. Whoever guesses it first will have the right to keep accounts. Only those who have the right to keep accounts can get the pancakes made by my mother.

Well, the problem has been solved perfectly again. You are the smartest person in the village. In the blockchain, the process of solving the puzzle is the process of striving for the right to keep accounts, commonly known as mining, and the person who obtains the right to keep accounts (node) receives a delicious big cake reward (Bitcoin). By the way, Bitcoin is also nicknamed big cake. Do you think it is God's will?

Seeing how good this method was, other people in the village followed suit. Whether they were borrowing money, having a baby, or giving a gift, as long as it involved money, they all learned to broadcast it on the loudspeaker. From then on, there were no more unclear and unclear things in the village. Because many people kept a small notebook, if someone cheated, they could just find a small notebook to check. Words alone are not enough, so writing is the evidence. If you don't believe one person's record, don't you believe everyone's record? This is the benefit and advantage of distribution.

At this point, you, who are as smart as me, must know what blockchain is. If we regard a notebook as a chain, then each page is a block, and the information recorded on each page is the transaction information within the block.

Although the scenario analogy I mentioned above is not so strict, it is much easier to understand than reading the white paper. You know, in order to understand what blockchain is, I learned a lot of Chinese, English, hash, password, block, consensus, Byzantine, double spending, etc. If I had seen such an easy-to-understand article earlier, I would have given it a thumbs up.

Of course, there are many other issues, such as how to ensure that the account keepers do not make false accounts together, and who gets the reward if two people solve the puzzle at the same time, which are not included in this article. But if you have thought of these questions, then congratulations, young man, you have a unique mind and active thinking, and you are a genius in learning blockchain. Because these problems have troubled cryptography experts for decades.