Block is a data container on a blockchain that holds a list of verified transactions. Once a block is filled with transactions and is finalized, it is added to the chain of previous blocks.

How a Block Works

Imagine a digital notebook where each page is a Block. When people make cryptocurrency transactions, those transactions are collected and stored in a pending queue. "Miners" on a blockchain take a group of these pending transactions and verify them. Once they have verified enough transactions to fill a page (a block), they add a unique digital signature to it. This signature also links the new block to the previous block in the chain, creating a secure, chronological record.

The first block on a blockchain is known as the "genesis block." Every subsequent block contains data that references the previous one, forming a tamper-proof chain. If anyone were to try and alter a transaction in a block, they would have to alter all subsequent blocks on the entire chain, which is virtually impossible on a large, decentralized network.

The Big Picture: Security and Transparency

The block is the fundamental building block of a blockchain. It is a critical component that ensures the security and integrity of the network. By bundling transactions together and linking them in a secure chain, blocks create a permanent and transparent record that anyone can verify. This structure is what makes blockchain technology so revolutionary for record-keeping.