They are not. They might be provided to try to provide a better explanation, but I don't even thing that this purpose is achieved. There are several sentences throughout the article that make no sense at all, like:

> A bitcoin, at its core, is a very simple data ledger file called a 'blockchain'. A blockchain's file size is quite small, similar to the size of a long text message on your smartphone.

I would recommend you to look at the [question you mentioned][1] , that actually have two really good answers, and ignored the first article.


  [1]: https://bitcoin.stackexchange.com/questions/12427/can-someone-explain-how-the-bitcoin-blockchain-works/42515#42515