Block Chain - Blockchain Technology (Foundation Concept)

Blockchain is a distributed digital ledger used to record transactions across multiple computers. Instead of storing data in one central place, the data is shared across a network of nodes. This makes blockchain highly secure and transparent.

Each block in a blockchain contains three main components: data, a hash, and the hash of the previous block. The hash is a unique digital fingerprint. If any data inside a block is changed, the hash also changes, making tampering easy to detect.

Blocks are linked together in a chain using cryptographic hashes. Because each block depends on the previous one, altering one block would require changing all subsequent blocks, which is practically impossible in large networks.

Blockchain works on a peer-to-peer network, meaning all participants (nodes) have equal authority. There is no central administrator controlling the system, which increases trust among users.

Transparency is another key feature. All transactions are visible to network participants, though user identities are usually protected using cryptographic addresses.

Blockchain ensures immutability, meaning once data is recorded, it cannot be changed or deleted. This is extremely useful in financial systems, supply chains, and record management.

Due to these properties, blockchain is widely used in cryptocurrencies, healthcare, voting systems, banking, and digital identity systems.