What is a blockchain and how does it work?

A blockchain is exactly what it sounds like it is: a chain consisting of blocks of information. These blocks are containers holding a record of transactions on the blockchain. In the case of Bitcoin, the transactions are primarily transfers of bitcoins.

What happens when a block is added to the chain?

And when a block is added to the chain, it cannot be changed. All information held in blocks is going to stay there as long as the blockchain exists. Blocks are added on top of one another in a linear way. One by one, they form a chain holding the entire history of transactions on the network.

Is the blockchain stored in a file?

Yes. The blockchain is stored in files that are shared in every full node of the network. Each full node has a full copy of the blockchain (files). Each file contains a certain amount of blocks. Each block contains a header and a list of transactions.

How does the ID of a block work?

Every block has an id which is calculated through the information in the block, and part of that information is the id of the previous block. In this way, the block knows after what block it comes in the blockchain. – Oscar Serna