Blockchain is a decentralized digital ledger designed to record transactions in a secure, transparent, and tamper-resistant way. Unlike traditional centralized systems, where a single authority controls the database, blockchain distributes data across thousands of nodes. Each node stores a copy of the ledger, ensuring that no single point of failure or manipulation can compromise the integrity of the system.
At the core of blockchain technology is the concept of blocks—bundles of data that contain transaction information. These blocks are linked together in chronological order using cryptographic hashes. Once a block is added to the chain, altering it becomes practically impossible without changing all subsequent blocks, which would require overwhelming computational power. This built-in immutability is one of blockchain’s strongest security features.
Blockchain relies on consensus mechanisms—algorithms that allow distributed nodes to agree on the validity of transactions. Popular mechanisms include Proof of Work (PoW), which requires solving complex mathematical problems, and Proof of Stake (PoS), where validators lock up tokens as collateral. These mechanisms prevent fraudulent activities, such as double-spending, and maintain trust within a trustless environment.