Is the blockchain distributed or decentralized?

What are your instincts when you hear the word "blockchain"?
What do you think of?
How do you define the blockchain?

In the beginning, my understanding was that blockchain was developed from bitcoin technology, distributed accounting, and data storage technology. Blockchain contains a variety of cryptocurrencies, various public chains, private chains, alliance chains, and various kinds of certificates.

Here is a keyword - distributed.
However, distributed computing and storage are not new technologies. It has been many years ago. Distributed computing communicates with each computer in the computer network and divides the problems into smaller parts and processes them separately to achieve the purpose of improving performance.

Bitcoin, on the other hand, not only distributes billing to computers around the world, but more importantly, it does not have a central server! A network of numerous computers (miners) does not rely on a central server to centralize data processing. Decentralized ledger technology makes bitcoin a digital cash system.

Decentralization is the blockchain innovation!
The following figure illustrates the differences between centralized, distributed and decentralized (from top to bottom).

![630a1436d5c960e5e6f595befdaeb92f.png]
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Although distributed and distributed network computers are scattered in different places, their main differences are: whether there is a central server and there is no centralized control center.

What is the difference between centralized, distributed and decentralized?
In a centralized network, all calculations are processed on a specific computer/server. For example, Web server.
Distributed networks, such as a large hosting company, are good examples. They serve customers around the world. All traffic is not calculated by a single server like a centralized network. But all decisions are still maintained and controlled by the hosting company.
Decentralized network with no central server and control center. Instead, it is up to the network to make its own decisions and control itself.

What are the advantages of using a decentralized network?
Decentralized networks are more reliable than centralized ones because without a central server, hackers are prevented from attacking the central server.
The decentralized model is more democratic than the centralized method. There is no central management organization and the users of the system control themselves.

What are the disadvantages of using a decentralized network?
Compared to centralized, the decentralized system is more costly to operate and maintain.
Decentralized networks, which rely on users, developers, and politicians to reach a common agreement, can sometimes be time consuming and inefficient.
Although the decentralized network is more secure and reliable, the implementation of decentralized computing is currently more costly and inefficient.

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