It is the main digital currency of the cryptocurrency market, does not depend on the banking systems we know, no one issues currency in a traditional way is earned by work when checking blocks. Its volume is 21 million and will never overcome that barrier which means that over time it will increase its value by comparing it with traditional money issued by governments.
The main criticism is the way in which this new digital money is used, since in some cases payments of illicit goods have been verified, however this is not an impediment since it must be taken into account that the money we use daily is also used for this purpose.