Imagine a city surrounded by several armies far apart commanded by several generals. The city is to be taken with the coordinated effort of all the armies at the same time, otherwise.
If all the armies attack at the same time, the city is taken. If all the armies go away nobody gets jurt but if just part of the armies attack the city, they´ll be defeated.
In order to attack, communitations among armies are critical. The problema is that generals need to take a decission even though they are far apart and can only communicate with horse messengers or flags. This comms can be corrupted, killed, stolen, or even the other generals may be lying so the rest get killed to gain more power.
Imagine a network in which all participants need to agree in which transactions to add, and in what order. In a centralized system, a central or main node receives the inputs and is recognized as the holder of the truth. But if there´s no central point how do you come up to an agreement?
Once people solved the BC as a solution for money people inmediately thought of more generic vehicles of money: insurance policies, work contracts, etc. This means the birth of a new Internet of VALUE besides the internet of INFORMATION.