Wat is Blockchain ?

Blockchain is a distributed ledger technology that records transactions across a network of computers in a way that ensures security, transparency, and immutability. Here are the key features and concepts of blockchain:

1. **Decentralization**: Instead of being stored in a single, central location, the blockchain ledger is distributed across many computers (nodes) in the network. Each node has a copy of the entire blockchain.

2. ** Immutability **: Once a transaction is recorded on the blockchain, it cannot be altered or deleted. This is ensured through cryptographic hashing, which links each block to the previous one in the chain.

3. **Transparency**: All transactions are visible to anyone with access to the blockchain. This public ledger allows for verification and auditability by anyone in the network.

4. **Security**: Blockchain uses cryptographic algorithms to secure data and ensure the integrity of the ledger. Each transaction is verified and agreed upon by the network through a consensus mechanism before it is added to the blockchain.

5. **Blocks**: Data in the blockchain is stored in blocks. Each block contains a list of transactions, a timestamp, and a reference (hash) to the previous block, forming a chain.

6. **Consensus Mechanisms**: To validate and add new transactions to the blockchain, the network relies on consensus mechanisms like Proof of Work (PoW) or Proof of Stake (PoS). These mechanisms ensure that all participants agree on the state of the blockchain.

Blockchain technology underlies cryptocurrencies like Bitcoin and Ethereum, but its applications extend beyond digital currencies. It can be used in various fields such as supply chain management, healthcare, finance, and voting systems to enhance security, reduce fraud, and increase efficiency.