The blockchain is the foundation of most cryptocurrencies - but its potential goes far beyond Bitcoin. As a tamper-proof, decentralized data structure, it enables trust without intermediaries and is transforming financial systems, supply chains, identity management, and more.
A blockchain is a digital, distributed ledger that records transactions chronologically and immutably. It operates in a decentralized way, meaning no single authority owns or controls the data. Each new block of data is cryptographically linked to the previous one - hence the name "blockchain".
How does a blockchain work?
Blockchains consist of a chain of blocks in which transaction data is stored. These blocks are arranged chronologically and linked together using cryptographic methods. Each block contains a hash (a kind of digital fingerprint) of the previous block, which makes the data structure particularly resistant to manipulation.
A key feature is decentralization. A blockchain is stored simultaneously on many computers (nodes). Once a transaction takes place, it must be verified by the majority of participants (e.g., through consensus mechanisms such as Proof of Work or Proof of Stake). This creates a transparent, publicly verifiable, and tamper-proof system.
Use cases and benefits
Originally developed for Bitcoin, blockchain technology has expanded far beyond that. Ethereum, for example, popularized the programmable blockchain with smart contracts. Today, blockchain applications can be found in logistics, healthcare, digital identities, or the tokenization of assets.
The advantages: high transparency, immutability of data, reduced dependence on central authorities, and increased efficiency in transactions. At the same time, there are challenges such as scalability, energy consumption (in proof-of-work-based blockchains), and regulatory uncertainty.