Blockchain technologies

Everyone gathers in a meeting room and Alex starts his explanation:

Alex: On a very high level, people consider blockchain just a special database, but it is not exactly that. A blockchain is a kind of digital shared archive of information that can be accessed only by authorized people (a network of people). A typical database stores data inside tables, but a blockchain stores data together in groups known as blocks. These blocks have a fixed storage capacity; when one block is filled, a new one is created for the remaining data, and it is linked to the previous block, thus forming a chain.

Harold: So, it is a chain of blocks and that’s why it is called blockchain. That’s evident.

Alex: Yes, exactly. All data gets chained in chronological order. Think of it as a block that is set in stone; it can’t be modified once stored. It becomes part of a timeline and is...