I recommend the ethereum whitepiper. It has a clear description of bitcoin and then goes on to describe other applications of the blockchain:<p><a href="https:&#x2F;&#x2F;github.com&#x2F;ethereum&#x2F;wiki&#x2F;wiki&#x2F;White-Paper" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ethereum&#x2F;wiki&#x2F;wiki&#x2F;White-Paper</a>