When tens of thousands of nodes keep a copy of the blockchain's data, some challenges can quickly arise, including data consistency and malicious nodes. To ensure the integrity of the blockchain, there are various consensus mechanisms that govern how network nodes reach an agreement. Let's now look into the major ones.

When a user initiates a transaction, such as sending a certain amount of cryptocurrency to another user, that transaction is broadcast to the network. Each node authenticates the transaction by verifying digital signatures and other transaction data.

Once the transaction is verified, it's added to a block along with other already verified transactions. Blocks are chained together using cryptographic methods, forming the blockchain. The process of verifying transactions and adding them to the blockchain is done through a consensus mechanism, a set of rules that govern how nodes on the network come to an agreement about the state of the blockchain and the validity of transactions.

In a decentralized blockchain network, there’s no central authority or intermediary that controls the flow of data or transactions. Instead, transactions are verified and recorded by a distributed network of computers that work together to maintain the integrity of the network.

When people talk about blockchain technology, they're often not just talking about the database. Blockchain technology powers applications such as cryptocurrencies and non-fungible tokens (NFTs), allowing people to collaborate and transact with each other without relying on a central authority.

A blockchain is a special kind of database, also called a decentralized digital ledger, that's maintained by numerous computers distributed around the world. Blockchain data is organized into blocks, which are chronologically arranged and secured by cryptography.

The earliest model of a blockchain was created in the early 1990s when computer scientist Stuart Haber and physicist W. Scott Stornetta employed cryptographic techniques in a chain of blocks as a way to secure digital documents from data tampering.

Haber and Stornetta inspired the work of many other computer scientists and cryptography enthusiasts, eventually leading to the creation of the first cryptocurrency powered by blockchain technology, Bitcoin. Since then, adoption of blockchain technology has gradually widened, and cryptocurrencies are used by an increasing number of people globally.

was created in the early 1990s when computer scientist Stuart Haber and physicist W. Scott Stornetta employed cryptographic techniques in a chain of blocks as a way to secure digital documents from data tampering.

Haber and Stornetta inspired the work of many other computer scientists and cryptography enthusiasts, eventually leading to the creation of the first cryptocurrency powered by blockchain technology. Since then, adoption of blockchain technology has gradually widened, and cryptocurrencies are used by an increasing number of people globally.

The vectors of development and the scope of application of smart contracts are growing rapidly, despite the relative novelty of the technology. Smart contracts are of interest in the fields of medicine, logistics, education and real estate.

Thanks to the blockchain, the result of the smart contract is permanently stored in the registry, which also makes it impossible to change or falsify it.

Types of smart contracts:

payment ― provides for the transfer of funds between the parties according to pre-known conditions; escrow ― act as intermediaries in the transaction. A smart contract holds assets until certain conditions are met; management contracts ― provide decentralized decision-making in the blockchain or DAO;

The first smart contracts allowed the transfer of cryptocurrencies from one address to another, if the user signs the transaction with a private key and has a sufficient number of coins in the account.

The next landmark event for the development of technology was the publication of the white paper of the Ethereum network in 2013

Smart contracts are not legally binding. However, they guarantee transparency and reliability of the transaction, since they work on decentralized digital registries, which means they are not controlled by an administrator or an organization.