The essence of blockchain

First of all, the main function of blockchain is to store information. Any information that needs to be saved can be written into the blockchain and read from it, so it is a database.

Secondly, anyone can set up a server, join the blockchain network, and become a node.

In the blockchain world, there is no central node. Each node is equal and stores the entire database.

You can write/read data to any node because all nodes will eventually synchronize to ensure the consistency of the blockchain.