Blockchain for dummies
Blockchain is a continuous sequential chain of blocks containing information built according to certain rules. The relationship between the blocks is provided not only by the numbering, but also by the fact that each block has its own hash sum and the hash sum of the previous block.
Changing any information in a block will change its hash sum. To comply with the rules for building a chain, a change in the hash sum must be canceled in the next block, causing a change in your hash sum. In this case, the previous blocks are not affected.

How the system works
Put simply, blockchain is a huge number of tables made electronically and combined into a single database. The technology is affordable due to its advantages and ease of use.
Distributed database
The potential of blockchain technology is difficult to overestimate, and its main advantage is a well-thought-out structure. The blockchain is based on a table that has hundreds of thousands or even millions of clones on the network. A distributed network is built taking into account the constant updating of information and its protection from external influences. The information is regularly reviewed and is under the control of the community. The technology has a number of advantages. The database is not stored on one server, but is located in many places at the same time. This ensures that the records are kept public and can be easily reviewed by any user. Source: bitcoin-fortress.site
Reliability and durability
Blockchain technologies - failure resistance. The information stored in a block is the same across the entire network, so the blockchain cannot be managed by a single authority or have a common point of failure. Since the introduction of the technology in 2008, there have been no significant failures in the system.
Almost all problems that arise are related to hacking sites or insufficient control of private keys by the cryptonet user. Simply put, the causes of blockchain application problems are human errors. An example to follow is the global Internet network, which has existed for more than 30 years and has shown its effectiveness.
Blockchain technology is not inferior to the Internet and is ahead of it in many ways. The features of a distributed ledger ensure maximum accuracy in accounting and user identification. With the help of blockchain, the legitimacy of transactions is ensured by creating records on millions of PCs.