How are blockchain blocks registered on the network?

Question

blockchain

Good day.
Recently I decided to study for myself how the blockchain works. And immediately there were many questions to which I could not find unambiguous answers. For example, I decided to take a blockchain for storing honey. these people. Each honey. institutions is a node.
1. After creating a block, how does the node send information about the new block (http, tcp, websocket) to the network? And does it send to all network members or to specific ones?
2. For example, there is a network of 5-6 nodes. At a certain point in time, 2 nodes generate a block each. How to decide which block will be written to the chain first? Given the fact that both blocks must be stored in the chain. And who adds these blocks to the chain? Those nodes that created them?
3. Is there any database used on the clients or how is the data stored on the client?

Answer 1

1. Your protocol . Double and angry.
2. Forwarding is at the transaction level, not at the block level.
3. Depends on the client. Bitcoin-qt works with LevelDb

Answer 2

How can a transaction and a block look like in the network I described (storage of medical data)?

Answer 3

vas3k.ru/blog/blockchain
about 2 - there are different consensuses, not necessarily the principle of proof of work,
the data in binary in files is simple, the blockchain is the base