Where not to learn about blockchain

I have been looking at writing a short introduction to blockchain (for managers and investors) and in looking at what other people have done, I have come across some really inadequate examples. Even Wikipedia (in English) does not clearly distinguish between the blockchain and applications such as cryptocurrencies. I have also looked at the Afrikaans and Dutch entries in Wikipedia but I think the German one says it best, in the first sentence.
"Unter einer Blockchain (auch Block Chain, englisch für Blockkette) wird eine Datenbank verstanden, deren Integrität (Sicherung gegen nachträgliche Manipulation) durch Speicherung des Hashwertes des vorangehenden Datensatzes im jeweils nachfolgenden gesichert ist."
This is simple and accurate! The two items below are, in my view, examples of unnecessarily confusing attempts to explain.

What is Blockchain – Explained in simple English https://mybroadband.co.za/news/internet/200218-what-is-blockchain-explained-in-simple-english.html

Chain introductory video – https://chain.com