The distributed ledger technology is borderless, permission less, unalterable, decentralised, censorship free, cryptographically and economically secure (based on game theory). In short it solves the big problem of 'single copy of assets' (including currency) that has plagued the internet world. In the internet world it is awesome to be able copy digital assets and data, however, it is a terrible outcome if you can copy assets such as currency, digital music, a car lease, a loan, a contract and any other asset where you want a single golden copy. So what do we do? We bring in big intermediaries like banks, lawyers and governments to provide 'trust'. There are many problems with this system of centralising assets, namely – hacking, modification, manipulation, corruption, control, blocking access etc etc. Bitcoin was the first application built on the distributed blockchain ledger and IMO will continue to be the 'golden' application, despite newer, better technologies (remember the protocols of the internet were not the best at their time but they were the protocols that were adopted and built upon, hence making them 'sticky'). So bitcoin is to distributed technologies what email is to the internet, the first application that will most likely hang around for a long time.