

Aaron Arnold
Aaron Arnold is a leading figure in financial technology and cryptocurrency, recognized for his innovative ideas in these domains. He has earned the trust of a global audience thanks to his expertise and his ability to clearly explain complex topics. Arnold plays an active role in advancing the crypto industry by sharing insights through educational platforms and public appearances. His efforts to promote blockchain technology have helped many newcomers grasp the fundamentals of digital assets and decentralized systems.
ABI (Application Binary Interface)
The Application Binary Interface (ABI) is a system-level interface that enables low-level binary interactions between two or more software applications. Fundamentally, the ABI defines the methods and data structures used to interact with smart contracts on blockchain networks.
In cryptocurrency development, the ABI is essential for building decentralized applications (dApps). For example, when a user interacts with a DeFi protocol via a web interface, the ABI ensures accurate data transfer between the application's frontend and the smart contract on the blockchain. Without a standardized ABI, compatible and functional decentralized applications would not be possible.
Access Control
Access control is a system for selectively restricting and managing access to locations, resources, or systems. It includes processes, technologies, and policies that ensure only authorized parties can gain access.
In the crypto ecosystem, access control is enforced through cryptographic keys, multi-factor authentication, and smart contracts with role-based permissions. For instance, in decentralized autonomous organization (DAO) protocols, access control determines which members can vote on proposals or perform administrative actions. A robust access control system is crucial for protecting digital assets from unauthorized use and cyber threats.
Bitcoin
Bitcoin is the first and most recognized decentralized digital currency, created by an anonymous individual or group using the pseudonym Satoshi Nakamoto in 2009. Bitcoin transformed the financial sector by providing an alternative to traditional fiat currencies and centralized payment systems.
Key features of Bitcoin include a fixed supply (maximum of 21 million coins), a decentralized validator network, and the use of blockchain technology for transaction transparency. Bitcoin is often called "digital gold" due to its function as a store of value. Over time, Bitcoin has become an established asset class, attracting both retail and institutional investors.
Blockchain (Blockchain)
Blockchain is a decentralized distributed ledger technology that records transactions across many computers, making it impossible to alter recorded transactions retroactively without changing all subsequent blocks.
Each block contains a set of transactions, a timestamp, and a cryptographic link to the previous block, creating an unbroken chain of data. This technology delivers transparency, security, and immutability. Blockchain is used not only in cryptocurrencies but also in logistics, healthcare, supply chain management, and other sectors requiring reliable data storage and verification.
Smart Contracts (Smart Contracts)
Smart contracts are self-executing agreements with predefined terms coded directly into software. When the specified conditions are met, the contract executes automatically, eliminating the need for intermediaries.
This technology removes the requirement for trusted third parties, reduces transaction costs, and accelerates contract execution. Smart contracts are widely used in decentralized finance (DeFi) for automating lending, asset exchanges, liquidity management, and other financial activities. For example, an automated market maker protocol can use smart contracts to instantly exchange tokens according to a set algorithm without a centralized exchange.
DeFi (Decentralized Finance)
DeFi is an innovative financial system that leverages blockchain technology to remove intermediaries and provide access to financial services to anyone with an internet connection.
Decentralized finance includes a wide range of applications, from lending and borrowing to derivatives trading and insurance. The primary benefits of DeFi are openness, transparency, and permissionless participation. Users maintain full control over their assets, and all operations are executed via smart contracts on public blockchains. In recent years, the DeFi ecosystem has seen substantial growth, attracting billions of dollars in total value locked (TVL).
NFT (Non-Fungible Tokens)
NFTs are unique cryptographic tokens that represent ownership of individual digital or physical assets, using blockchain technology to verify authenticity and ownership rights.
Unlike fungible tokens (such as Bitcoin or Ether), each NFT is unique and cannot be exchanged one-to-one for another token. NFTs have found widespread use in digital art, collectibles, gaming, virtual real estate, and product authentication. NFT technology enables content creators to monetize their work and connect directly with audiences, bypassing traditional intermediaries.
Ethereum
Ethereum is a decentralized platform for creating and running decentralized applications (dApps), supporting smart contracts through its native cryptocurrency, Ether (ETH).
Launched in 2015 by Vitalik Buterin and a team of developers, Ethereum extended blockchain technology beyond simple value transfers. The platform uses the Ethereum Virtual Machine (EVM), which enables developers to build advanced decentralized applications across sectors such as finance, gaming, and social media. Ethereum underpins most DeFi protocols and NFT projects, making it the second-largest cryptocurrency by market capitalization after Bitcoin.
Wallet
A cryptocurrency wallet is a digital tool for securely storing and managing crypto assets. Wallets come in several types: hot (internet-connected) and cold (offline), as well as software and hardware versions.
Each wallet contains a pair of cryptographic keys—a public key (address for receiving funds) and a private key (a secret code for authorizing transactions). Wallet security is essential because the loss of a private key means irreversible loss of access to funds. Modern wallets offer added features such as support for multiple blockchains, built-in exchanges, and DeFi protocol integration.
Mining (Mining)
Mining is the process of validating blockchain transactions and creating new blocks by solving complex cryptographic problems. Miners use computing power to verify transactions and secure the network.
Miners are rewarded with new coins and transaction fees for their work. Mining requires significant investments in hardware and electricity, especially for blockchains that use the Proof-of-Work (PoW) algorithm. As technology has advanced, different mining methods have emerged: solo mining, pool mining, and cloud mining, each with distinct pros and cons.
Staking (Staking)
Staking involves locking up cryptocurrency in a blockchain network to support its operation and earn rewards. This process is used in blockchains with a Proof-of-Stake (PoS) consensus algorithm.
Participants in staking—known as validators or delegators—commit their tokens as collateral, giving them the right to validate transactions and produce new blocks. In return, they earn rewards in the form of additional tokens. Staking is a more energy-efficient alternative to mining and provides passive income for crypto holders. Many modern blockchains, including Ethereum 2.0, Cardano, and Polkadot, employ various staking mechanisms.
Gas Fee
Gas fee is the charge required to complete transactions and execute smart contracts on the Ethereum network and compatible blockchains. The fee amount depends on the operation's complexity and current network load.
Gas is measured in specific units (gwei for Ethereum) and acts as a prioritization mechanism—users willing to pay higher fees receive faster transaction confirmations. The gas system also protects the network from spam and infinite loops in smart contracts. High gas fees during peak periods are a core blockchain scaling challenge, which has led to the development of Layer 2 solutions to reduce transaction costs.
Yield Farming
Yield farming is a strategy for earning returns by locking assets in decentralized finance (DeFi) protocols in exchange for rewards. Participants provide liquidity to DeFi platforms, earning interest, fees, and governance tokens.
Yield farming may involve various strategies: providing liquidity on decentralized exchanges, lending on lending platforms, participating in synthetic asset protocols, and more. While yield farming can offer high yields, it also involves significant risks, including impermanent loss, smart contract vulnerabilities, and token volatility. Success in yield farming requires deep knowledge of protocol mechanisms and ongoing market monitoring.
Blockchain is a distributed data storage technology structured as a chain of blocks. Cryptocurrency is a digital asset that operates on blockchain technology. Key concepts include decentralization, transparency, immutability of records, and cryptographic security for transactions.
Mining is the process of validating transactions and adding new blocks to a blockchain. A wallet is software for storing and managing digital assets. A private key is a unique code that gives you full control over wallet funds. Never share your private key with anyone.
Bitcoin is the first standalone cryptocurrency with its own network. Ether is the native cryptocurrency of the Ethereum blockchain, which supports smart contracts. Tokens are digital assets issued on existing blockchains (such as Ethereum) and serve various purposes: payments, voting, staking.
A smart contract is self-executing program code on a blockchain that automatically enforces agreement terms without intermediaries. It stores deal logic and activates when preset parameters are met, providing transparency and transaction security.
DeFi uses blockchain and smart contracts to automate financial services without intermediaries, providing transparency and self-custody of assets. CeFi relies on centralized platforms and companies that manage user funds, which requires trust in third parties.
Gas fee is the payment required to process a transaction on the blockchain. Transaction confirmation is the verification and inclusion of a transaction in a block. Consensus mechanism is the protocol that enables the network to agree on the validity of new blocks and data.
An NFT is a unique digital asset with distinct characteristics, stored on a blockchain. Unlike cryptocurrencies (which are fungible), each NFT is one-of-a-kind and cannot be replaced by another. NFTs are used for digital art, collectibles, and ownership rights.
A hash is a unique code that acts as a fingerprint for a block. A public key is an address for receiving funds. A signature proves that the owner of a private key has authorized a transaction. Together, they provide security and transparency for the blockchain.











