Blockchain is a decentralized, distributed, immutable digital ledger or ledger that securely records transaction data across a large number of computers (nodes). It primarily uses cryptography to eliminate the need for trust and intermediaries.
Basic definition & concept
A blockchain can be thought of as a public database, where data can only be added to, but once recorded, it cannot be changed or deleted. A ledger is a digital account book that records all transactions that have occurred over time. The information is not owned by a single server or organization (such as a bank), but is distributed among thousands of users on the network. This eliminates the risk of a single point of failure. Due to cryptography, once a transaction is verified and added to a block, it is impossible to change it.Structure of the blockchain
A block is the basic unit of data. Each block usually contains transaction data, a time stamp, and a hash. A transaction is a record of all valid transactions that have occurred within a certain period of time (e.g., who sent whom how much money). The time stamp is when the block was created. A hash is a unique cryptographic fingerprint of the contents of the block. This hash is a short, fixed-length code that changes completely even if the contents of the block change slightly. Blocks are linked to each other by forming a chain. Linking Each new block contains the hash of its previous block. This establishes a mathematical connection between the chain. If a hacker wants to change the data in a block in the middle of the chain, the hash of that block will change. As a result, its hash will not match the next block in the chain, and the rest of the chain will be invalidated or invalidated. This linking ensures immutability. A node is any computer participating in the network that stores a full or partial copy of the blockchain. These nodes maintain the security of the network and verify transactions.How It Works
Blockchain works in four main steps, which ensure that data is secure and added based on consensus. At the beginning of a transaction, a user initiates a transaction using his digital signature (Private Key). The transaction is broadcast to the network. Then, nodes in the network verify the transaction. They ensure that the person making the transaction has enough balance to make the transaction. The signature is valid and the person making the transaction really owns that wallet. Then, the verified transactions are combined to create a new block. This new block is determined by the rules of the network using a consensus mechanism such as Proof-of-Work (PoW) or Proof-of-Stake (PoS). Once a majority of the nodes in the network accept a new block and the consensus is valid, the block is cryptographically added to its previous block and permanently added to the ledger.