I believe that Bitcoin is unique because it not only represents a currency that has all the characteristics of currencies in circulation as we know it and adds to it additional layers of protection that prevent any central power from controlling or manipulating it, but also because it represents an integrated payment system and built very carefully through the mining system that guarantees confirmation Transactions without the need for a third party and in complete confidentiality.
Agree! and it is indeed unique because his has been the first and only major technology that aimed to innovate (or at least provide an alternative to) the way people think about money in centuries.
What I wanted to say is that it is more appropriate to compare Bitcoin to gold than to try to match it to cash.