What is Blockchain? (6.1 Crypto Foundation)

[00:02] will talk about what a blockchain actually is. I believe that here the blue ones. Beginners, everyone already knows what a blockchain is in general. You know the blockchain-chain block, the whole idea of ​​decentralization and

[00:15] privacy, that is, in general, how it is arranged. The main idea is that every action in our case regarding financial transactions, a

[00:27] transaction is recorded in the so-called chain, that is, some transaction was made here. We call it a Hash, and in the next block. Where to make the next transaction, there is data from this

[00:43] transaction in the next block. We also have some kind of Hash here. In the next block, there is data from previous transactions for comparison. I call these ordinary store receipts, which contain data

[00:58] about the buyer who was in front of you, and so on. That is, in each new receipt so on. That is, in each new receipt there is data about the previous receipt, everything is openly everything can be tracked. It is believed that the blockchain cannot be hacked. But in

[01:12] fact, this is not at all the case. There have been precedents when blockchains were hacked. Yes, it is difficult. If someone, for example, wants to change the data of this block, then the Incorrect because it will contain a transaction from this block, so it goes

[01:28] here, it will pull and it simply will not converge and the entire blockchain will stop. This is enormous computing power is needed, a lot of transactions happen, but that's not all. There is such a concept of consensus when the majority of system participants.

[01:44] Hello, this module is correct, and there are many participants. In the case of Bitcoin, many participants. In the case of Bitcoin, these are miners. So, if the block is incorrect, it is really possible to hack it. Make an incorrect block if 51 percent of the

[01:57] participants say that the block is not correct. This is how it should be, even if it is incorrect, then everyone considers the blockchain hacked. In fact, these two conditions must be met. At the moment, it is unlikely. But there are ways. If the power is in the hands of

[02:13] several people who can agree among themselves, they can do this. I am telling you about the disadvantages of blockchains. And in general, blockchains are different. This is the scheme that everyone talks about, maybe they read it somewhere on YouTube,

[02:26] watched it in different words, but the same thing is said, that is, in general. Yes, that's how it all works, but in fact, it's like an operating system. One is more vulnerable, the other is less vulnerable. Let's say Windows is much more susceptible to

[02:41] various viruses than iOS. Also, from the block, for example, one is really more vulnerable, a new blockchain is created, the developers of which say I am better. We don't have this vulnerability, we fixed it, but there are other problems, for example, the

[02:58] Bitcoin blockchain, it's not particularly scalable, it can't handle many transactions and transfers are slow, they create blockchains that say our transactions are fast. We're great. The next disadvantage is miners, their machines, their hardware, it

[03:14] calculates a huge amount of absolutely unnecessary information, just absolutely useless calculations that actually relate to executing transactions. I don't know the percentage, but it could be some

[03:30] thousandth of a percent, the rest is all stupidly useless calculations, since at a certain point in time, a certain amount of Bitcoin is released, regardless of how many miners there are, no more or less Bitcoins will be

[03:46] released. That is, if one person mines, he will take this entire volume. If two people mine, the volume is divided between them, but the difficulty increases in order not to speed up mining, and absolutely useless mathematical calculations are added to this complexity.

[04:01] mining, and absolutely useless mathematical calculations are added to this complexity. slow. It also simply has huge energy costs, clearly seeing this, a new blockchain is created, another one that says, "We are less

[04:17] energy-intensive." And these are the problems in various blockchains. There are a lot of them. And various blockchains. There are a lot of them. And that's why they are being created. 1 2 3. There are also a lot of blockchains now and they are constantly being released. It was not for nothing that I gave you

[04:32] examples of the Windows and iOS operating systems, and both are operating systems, but each has its own feature. If Linux is Android and a bunch of other things, and the

[04:44] two also have their own add-ons. The same thing with blockchains that are blockchains of level 2 and higher, often different blockchains cannot work with each other. That is, there is one blockchain and there is blockchain 2. They do

[05:01] not work with each other. For this, bridges are created that allow them to work. That is, blockchain is the basis of the entire system. There are many of them, they are being created, refined, and will be created. Also, each

[05:13] blockchain has its own token. For example, Bitcoin also issues bitcoins to reward miners who service transactions, and in this service transactions, and in this case, it is a token. This is a cryptocurrency, it

[05:27] is useful, it is needed for the blockchain itself to work, because the blockchain simply will not work, no one will need it, and thus it turns out that tokens are released, cryptocurrency is released, coins are released that are

[05:40] useful and needed, and this is the main idea I now want to convey to you that blockchain is the basis. The foundations of the entire cryptocurrency world, all coins. All

[05:52] tokens live inside a blockchain, and each blockchain has its own pros and cons, and each blockchain has its own token, and the better the blockchain performs, the higher the value of their token we will see. For now, just remember this thought. This is it

[06:07] For now, just remember this thought. This is it in this lesson. See you all in the next one.