You hear often about ‘Blockchain and Bitcoin’. But what actually is ‘blockchain’? To explain this we’ll introduce you to these students living together These four students share everything: groceries, chores, and the costs of internet, water, gas and electricity. They keep track of all expenses in a notepad. They also make a note when someone pays in advance for someone else. However, one roommate seems to be saving an extraordinary amount money at the end of the month. The other students don’t trust this: is he cheating? What’s next? They can ask the landlord to keep track of the expenses, but they don’t want the landlord to know everything about them. There is another solution: all roommates get an identical copy of the notepad, in which everyone makes notes about everything. Nobody can secretly add a zero, forget about something, or delete something. Because the notepads will no longer be identical. The students often check up to see whether the notepads still match up. This is obviously a bit cumbersome: keeping track of all this on paper. But this is basically how the blockchain works, be it digitally. A common and distributed ledger, without a landlord, without a bank. Made in such a way all roommates can trust it. All trades are tracked in the blockchain, and these trades must be verified by other users in the blockchain network. In the blockchain you basically only send digital information. With digital coins like Bitcoin and Ethereum you send digital money, with a bit of extra information about the sender and the destination. But you can do more with bockchain besides just sending money and keeping track of a shared notepad. For this we’ll go back to the four students. One of the students leaves and another one joins in his place. Via the blockchain the expenses can be easily shared with this new roommate. Without one of the students getting a disadvantage if the new student doesn’t pay. You can also program things in the blockchain. For example: when the students get money back at the end of the month, this money becomes available only as soon as chores have been done and the other students verified this. The blockchain can be used for all kinds of things: everything you do or share can be kept track of in the blockchain. Outside of the student house as well. There is no longer a need for notaries, banks or even the government anymore. For this reason experts think our entire lifes could be revolving around the blockchain.