 What is blockchain technology? The financial crisis of 2008 increased distrust towards intermediaries or trusted third parties, such as, in this case, banks. In the wake of this crisis of trust, a description of the first blockchain application, the now well-known virtual currency, Bitcoin, was published by the pseudonym Satoshi Nakamoto. As intermediaries, banks ensure that one cannot spend the same money more than once in the digital world. For the first time, however, the cryptocurrency Bitcoin managed to address the double-spend problem for electronic transactions without the need for a trusted third party. This inspired blockchain enthusiasts to picture a utopian world without the need for centralized trusted third parties, such as banks, notaries, social media companies, administrative authorities or even judges. The success of Bitcoin made many actors interested in the underlying technology. Could it be more than just a hype? To assess this, we first need to understand what blockchain technology is. Well, instead of being centralized, blockchain functions in a distributed manner. It is a so-called distributed ledger technology, or DLT. What does that mean? Well, blockchain is a data structure, a ledger, to which data can be added in blocks that are chained or linked to each other. The data is collectively shared and kept secure by the computers or participants in the network. These participants are called nodes. Instead of registering data or transactions in one or more physical ledgers, blockchain does this electronically and in a distributed way, without the need for the involvement of a central trusted third party. In combination with algorithms called smart contracts, blockchain can facilitate the registration of information, the exchange of value and the execution of rules. The participants, the nodes in the distributed network, verify transactions and collectively guarantee the immutability of the data stored onto the ledger. To achieve this, blockchain uses a consensus mechanism to ensure that the participants in the distributed system authenticate and validate transactions on which the network agrees. Once transactions are registered in the blockchain, they become immutable and can no longer be tampered with. Blockchain is thus an effective way to prevent fraud without the need for an intermediary actor to ensure trust between parties. As a result, blockchain-based smart contracts, which are deterministic if A then B algorithmic rules, enable the execution and enforcement of rules and transactions between parties who do not fully have to trust each other. In practice, no one can unilaterally influence the correct execution of the smart contract. The need for trust, of course, does not disappear, but it is said that trust in institutions is being replaced by trust in technology. In the wake of Bitcoin's popularity, so far more than 4,000 virtual currencies have emerged, representing more than $250 billion. Moreover, both private companies and governments have been developing a plethora of blockchain use cases, proof of concepts and pilots. Admittedly, many of these have not yet been fully implemented into real-life applications. Although the technology is still maturing, blockchain is rapidly evolving and might have a substantial future potential as part of our networked society.