Blockchain technology is the great invention of smartest minds. I have a higher technical education and I'm convinced it is. You can read about Blockchain on Wikipedia, for example. Decentralization and encryption for storing data is our present and future.
But using this technology for mining money is the biggest fraud in the modern human history in my opinion. Enormous electricity and computing resources are wasting every day. Bitcoin is the calculations of math function which calculates nothing useful for humanity at all. All wasted resources could be used, for example, in calculations for protein folding researches which Stanford university do for many years. You can google about 'Folding@home' project, my computer was a part of it for few months long time ago, unfortunately it was too much for my graphics card, it failured so I stopped my participation there.