Overview
A blockchain is a decentralized, distributed digital ledger that records transactions across a network of computers. This technology ensures that once data is recorded, it becomes nearly impossible to alter retroactively without changing all subsequent blocks. By distributing the ledger across many participants, the system removes the need for a central authority, such as a bank or government, to validate information.
Initially introduced as the underlying technology for the first cryptocurrency, blockchain has evolved into a foundational infrastructure for various digital applications. It serves as a transparent and secure method for documenting ownership and activity in a digital environment. As of 2026, many global industries continue to explore its potential for enhancing supply chain management and digital identity verification.
How It Works
The system functions by grouping data into "blocks" that are linked together in a chronological "chain." Each block contains a unique cryptographic hash, the hash of the previous block, and a set of transaction data. This structure creates a secure link between blocks, meaning any attempt to change data in an old block would invalidate the cryptographic signatures of the entire chain.
To add new information to the ledger, the network must reach a consensus through specific rules or mathematical algorithms. Independent computers, known as nodes, work together to verify that new transactions are valid according to the protocol. Once the network agrees, the new block is added to the ledger and updated across all participating nodes simultaneously, ensuring everyone has the same version of the truth.