What is Blockchain

Blockchain is a distributed digital ledger technology where data is stored in sequential “blocks,” each cryptographically linked to the previous one, forming an immutable chain across a peer-to-peer network. 

In simple terms, instead of one central database, every participant in the blockchain network holds a copy of the ledger. When a new record (block) is added, it is broadcast to all participants, who validate and append it. Because each block contains a cryptographic hash of the previous block, altering historical data would require changing all subsequent blocks and convincing the majority of network participants to accept those changes, making tampering extremely difficult. 

Why It Matters:

Blockchain’s tamper-resistant structure fosters trust without needing a centralised intermediary. This underpins cryptocurrencies like Bitcoin but also extends to applications such as supply-chain tracking, digital identity management, and smart contracts that self-execute when predefined conditions are met.