A blockchain is an online database that stores information. This information is stored in blocks, and these are subsequently joined to each other in order to form a chain (blockchain). If data is added or changed in the blockchain, then this affects all instances of this data at all locations that this data is stored in. This makes it fully transparent and decentralized, and it is therefore not possible to spend the same cypto coin twice. What blockchain precisely is and how it works, we will explain to you in our free video.