Bitcoin Forum

I am very green in Cryptocurrency. I knew it is based on Blockchain and the data in the chain cannot be amended. However, I have one question, data eventually need hardware to store, right? Since the blockchain is decentralized, the chain data would be saved to where ? Which storing devices are saving those data ? thank you

The data is stored on thousands of computers around the world. These are the nodes. You can set up a node as well and store it.

Ofcourse.
  Blockchain is like a shared Book many authors of a specific topic can contribute to. Every one of the author has a copy of the Book and anyone can contribute or add meaningful messages/data to the Book whenever they want to. Whenever someone adds something to the book, others writers with thesame copy of the book verify the message/data to make sure it's OK/right before accepting it and recording in their own copies. It's basically thesame Book and topic with over thousands of writers updating it with more data.
 Blockchain operate in similar manner. It's like pages of book binded together in a book form and stored in multiple computers controlled by different people around the world. Anyone can add data to the Blockchain... once the data is approved, it's distributed accross multiple Blockchain nodes in thesame Network

This is correct @OP.

--> https://101blockchains.com/where-blockchain-is-stored/

As the Poker Player replied, each full node keeps a copy of the entire blockchain database. Thus, synchronization is required once the Bitcoin core client is started.

When you run a node, it downloads the blockchain from nodes on other computers to your own.

That's how the whole system stays decentralized. Any why if you just start a cryptocurrency any people running your node then you won't have a blockchain for it.

I feel, a pictorial reference may give you an idea to understand about the decentralized servers aka nodes vs centralized servers.

https://i.imgur.com/vCn7dFA.png

In decentralized server, each and every node acts as a servers and cross verifies the block changes with all other nodes and verifies it, so if any node try to change the actual value then the node will be eliminated and the actual change will remain in the server.

The full node saves the data. There are many full nodes in the world, you can read your trading information on the side.

every piece of software that is deemed 'fullnode' software, is handed a copy of the blocks. they all store them on their hardrives
they can all then gossip with each other their latest block ID they have and get any blocks they dont have. and independantly validate the block data matches the ID and then the data meets the rules of bitcoin. to then store that block if it passes all rules

then all the fullnodes are then following the same chain of blocks as they all in agreement of the latest valid block ID.

there is no need to gossip every block ID from block 1 to latest block you have, to compare to other people.
nor need to resend every blocks data just to compare to everyone else..

because the latest block you have contains the chain of previous block ID so by having all the blocks upto say block 690,000. means block 690,000's ID is unique to that exact sequence of data from block1 to 690,000

so as long as when you have validated all the blocks. the block 690,000's ID would match another nodes block 690,000 if they also have all the valid data.
and so as long as everyones block 690.000 id's match each other. you confirm you all have the exact same data back to block 1