What is Blockchain ?

Blockchain is a distributed ledger technology that allows data to be stored in a secure, transparent, and tamper-evident manner. In a it, data is stored in blocks, which are linked together in a chronological chain. Each block contains a set of transactions, and once a block is added to the chain, it cannot be altered or deleted without invalidating the entire chain.

The technology relies on a network of computers, known as nodes, which maintain a copy of the it and validate transactions. Transactions are verified through a consensus mechanism, where a majority of nodes must agree that a transaction is valid before it is added to the blockchain.

The most well-known example of it is Bitcoin, the first and largest cryptocurrency. However, it technology has many other potential applications beyond digital currencies, such as in supply chain management, digital identity, voting systems, and more.

Blockchain Code

it code can be written in various programming languages such as C++, Python, Java, and Solidity.

Here’s a simple example of a it implemented in Python:

import hashlib
import json
from time import time

class Blockchain:
     def __init__(self):
          self.chain = []
           self.current_transactions = []
           self.new_block(previous_hash=1, proof=100)

     def new_block(self, proof, previous_hash=None):
           block = {
                'index': len(self.chain) + 1,
                'timestamp': time(),
                'transactions': self.current_transactions,
                'proof': proof,
                'previous_hash': previous_hash or self.hash(self.chain[-1]),
}
           self.current_transactions = []
           self.chain.append(block)
           return block

       def new_transaction(self, sender, recipient, amount):
           self.current_transactions.append({
                 'sender': sender,
                 'recipient': recipient,
                 'amount': amount,
        })
        return self.last_block['index'] + 1

 @staticmethod
         def hash(block):
                block_string = json.dumps(block, sort_keys=True).encode()
                return hashlib.sha256(block_string).hexdigest()

 @property
          def last_block(self):
          return self.chain[-1]

In this example, we define a it class that has the following methods: