Blockchain is a decentralized, distributed database that records information as a sequential chain of blocks linked by cryptographically secured connections. Each block contains transaction data, timestamps, and a unique identifier, making the system immutable and secure.

Simply put, blockchain is a digital ledger where each entry (block) is linked to the previous one and verified by multiple participants in the network. It's like pages in a logbook that cannot be removed or tampered with, and a copy of this logbook is stored with all participants simultaneously.

A key feature of blockchain is the absence of a central governing authority. The network is managed by numerous participants (nodes) that verify and validate each new entry. This makes blockchain reliable, tamper-proof, and ideal for financial transactions, creating smart contracts, and storing data.

Let’s break down the key concepts that describe blockchain infrastructure:

1. Blockchain Platforms: Software that enables the creation and management of blockchains. Examples include Ethereum, Bitcoin, Hyperledger, and others.
2. Cryptocurrencies: A digital form of money that exists only online and operates using blockchain technology. Blockchain is not only used for creating and managing cryptocurrencies like Bitcoin, Ethereum, and Ripple but also for many other applications. Cryptocurrencies remain one of the most popular implementations of blockchain, providing secure and transparent financial transactions.
3. Smart Contracts: Computer programs that automatically execute the conditions embedded in their code. Smart contracts operate on the blockchain and allow for automated processes without intermediaries, ensuring transparency and security.
4. Decentralized Applications (DApps): Applications that run on the blockchain without centralized control or management. DApps provide various services such as financial tools, social networks, games, and more.
5. Digital Wallets: Software or hardware devices that allow users to store and manage their crypto assets. Digital wallets provide secure storage for private keys and enable blockchain transactions.
6. Mining: The process of verifying and adding new transactions to the blockchain. Miners use computational power to solve complex mathematical problems and receive rewards for their work. This is why mining is often referred to as cryptocurrency "extraction."
7. Consensus Algorithms: Mechanisms that ensure agreement among blockchain participants about the state and order of transactions. Key algorithms include:

• Proof of Work (PoW): Participants (miners) solve complex mathematical problems to confirm transactions and add blocks to the chain. This method requires significant computational resources and is used in networks like Bitcoin.
• Proof of Stake (PoS): Participants stake their tokens to run a node, confirm transactions, and propose new blocks. The more tokens staked, the higher the chance of adding a block. PoS does not require specialized equipment or high electricity usage and is used in networks like Ethereum 2.0.
• Delegated Proof of Stake (DPoS): A PoS variation where participants vote for trusted delegates who then confirm blocks on their behalf. This method speeds up the process and enhances scalability, as seen in the EOS blockchain.

8. Application Programming Interfaces (APIs): Tools and protocols that allow developers to create applications interacting with the blockchain. APIs provide access to various blockchain functions and services.

These are just some of the key services and components of blockchain infrastructure. Depending on specific needs and use cases, there may be additional blockchain-related services and components.

A smart contract is a program that automatically enforces the terms of an agreement between two parties without intermediaries.

For example, if you are selling a digital product, a smart contract can be set up as follows: the buyer transfers payment, and once the payment is received, the code automatically delivers the product. All actions are predefined in the program, which checks the fulfillment of conditions and triggers the next step in the process.

The contract operates within a blockchain—a decentralized database. Here, transaction details are recorded as immutable entries. The smart contract verifies that the terms of the deal are met; if something goes wrong, the transaction does not proceed. This ensures that both parties fulfill their obligations. Additionally, the blockchain provides transparency and secures participant data through encryption.


Advantages of Smart Contracts

• Speed: Smart contracts enable transactions to be completed in seconds, regardless of the distance between the parties. Everything can be done directly via a smartphone.
• Independence: No intermediaries are involved in the transaction. The guarantor of the deal is the code itself, ensuring transparency and eliminating the risk of human error.
• Reliability: Information on the blockchain is immutable. If one party fails to meet their obligations, the smart contract automatically protects the rights of the other party.
• Error-Free Execution: The process is fully automated, eliminating the risk of human error and ensuring precise execution of all terms.

An NFT (Non-Fungible Token) is a unique digital token recorded on a blockchain. Unlike standard cryptocurrencies like Bitcoin or Ethereum, NFTs cannot be divided into smaller parts or replaced by another token because each one is unique.

Like cryptocurrencies, NFTs can be stored in crypto wallets, bought, and sold. However, unlike BTC or ETH, which can be exchanged for the same quantity of similar coins, an NFT is a unique digital counterpart of an item that cannot be divided.

The key properties of NFTs are their uniqueness, immutability, and the ability to confirm ownership. Each NFT contains unique data that makes it one of a kind. Information about the token is recorded on the blockchain, where it cannot be altered or deleted, ensuring transparency and security. NFTs also serve as proof of ownership of a specific asset, whether it's a piece of art, music, an in-game item, or more. These qualities make NFTs a valuable tool for managing digital assets.

Crypto wallets are digital tools for storing, sending, and receiving cryptocurrencies. They allow users to manage their assets by providing access through keys or phrases that ensure the security of funds.

Among popular hot wallets that support stablecoins are Trust Wallet, MetaMask, Atomic Wallet, Exodus, Coinbase Wallet, and Savl. For storing large amounts, hardware (cold) wallets such as Ledger or Trezor are recommended.

When choosing a wallet, consider its compatibility with the blockchain your coins operate on (e.g., Ethereum, BNB Chain, Tron, or Polygon), its security level, ease of use, and available features such as support for multi-currency operations or integration with decentralized applications.