Blockchain Basics

A blockchain design pattern that allows smart contract wallets to replace externally owned accounts, enabling programmable transaction logic and improved UX.

A unique alphanumeric identifier on a blockchain that serves as a destination for sending and receiving cryptocurrency.

The first and largest cryptocurrency by market capitalization, created in 2009 by the pseudonymous Satoshi Nakamoto as a peer-to-peer electronic cash system.

A container of bundled transactions that is cryptographically linked to the previous block, forming the sequential chain of a blockchain.

A web tool that allows users to search, view, and verify transactions, addresses, blocks, and other data on a blockchain in real-time.

The newly created cryptocurrency awarded to miners or validators for successfully adding a new block to the blockchain.

The average time between consecutive blocks being added to a blockchain, determining transaction throughput and confirmation speed.

A distributed, immutable digital ledger that records transactions across a network of computers, making data tamper-resistant and transparent.

A cryptocurrency storage device or method that keeps private keys completely offline, providing maximum security against digital threats.

The mechanism by which distributed network participants agree on the state of the blockchain, ensuring all nodes share the same transaction history.

The method by which a blockchain network agrees on the current state of the ledger, ensuring all nodes validate and accept new transactions without a central authority.

The distribution of power, control, and decision-making away from a central authority across a network of participants.

A self-sovereign identity system where users control their credentials and personal data through blockchain-based verification without centralized authorities.

The automatic recalibration of mining difficulty that maintains consistent block production times regardless of changes in total network hash power.

The most common Ethereum token standard defining a universal interface for creating and transferring fungible tokens on the Ethereum network.

The second-largest cryptocurrency and the leading smart contract platform, enabling decentralized applications, DeFi protocols, and programmable money.

The runtime environment that executes smart contract bytecode on Ethereum and EVM-compatible chains, serving as the standard for programmable blockchain computation.

A venue where crypto assets are bought and sold, either as a centralized order book that holds custody or as a decentralized protocol on-chain.

The point at which a blockchain transaction is considered irreversible and cannot be altered, with different chains achieving this at different speeds.

A change to a blockchain's protocol that creates either a temporary or permanent divergence in the chain, splitting it into different versions.

The transaction fee paid to blockchain validators for processing and confirming transactions, denominated in the network's native token.

The maximum amount of computational work a transaction or block can perform, preventing infinite loops and controlling blockchain resource usage.

Techniques for minimizing the computational cost of blockchain transactions, reducing fees for users and improving protocol efficiency.

A period of extreme network congestion where users aggressively bid up transaction fees to compete for block inclusion, typically during high-demand events.

The smallest practical denomination of Ether used for measuring gas prices on Ethereum, equal to 0.000000001 ETH (one billionth of an Ether).

A pre-programmed event in Bitcoin's protocol that cuts the mining block reward in half approximately every four years, reducing new supply issuance.

A permanent divergence in a blockchain creating two separate chains when nodes adopt incompatible protocol rule changes.

A fixed-length alphanumeric string produced by a cryptographic hash function that uniquely represents input data, fundamental to blockchain security.

A cryptocurrency wallet connected to the internet for quick transactions, offering convenience at the cost of reduced security compared to cold storage.

The ability of different blockchain networks to communicate, share data, and transfer assets between each other without intermediaries.

The base blockchain network (like Bitcoin, Ethereum, Solana) that processes and finalizes transactions on its own consensus mechanism.

A scaling solution built on top of a Layer 1 blockchain that processes transactions off-chain while inheriting the security of the base layer.

The live, production blockchain network where real transactions with actual monetary value occur, as opposed to testnets.

The holding area for unconfirmed transactions waiting to be included in a block, where fee levels determine transaction priority.

A data structure that efficiently summarizes and verifies large sets of transactions using cryptographic hashes, enabling lightweight blockchain verification.

The process of using computational power to validate transactions and add new blocks to a proof-of-work blockchain, earning newly minted cryptocurrency as a reward.

A computer that participates in a blockchain network by maintaining a copy of the ledger, validating transactions, and relaying information to other nodes.

A unique blockchain token representing ownership of a specific digital or physical asset, where each token is distinguishable from every other.

A one-time-use number in proof-of-work mining that miners iterate through to find a valid block hash below the difficulty target.

A decentralized network of nodes that collectively source, validate, and deliver external data to smart contracts, providing tamper-resistant real-world information.

A cryptographic audit mechanism that allows exchanges to prove they hold sufficient assets to cover all customer deposits without revealing individual account details.

A consensus mechanism where validators are selected to create blocks based on the amount of cryptocurrency they have staked as collateral, replacing energy-intensive mining.

A consensus mechanism where miners compete to solve computational puzzles to validate transactions and create new blocks, consuming energy to secure the network.

A Layer 2 scaling solution that executes transactions off-chain and posts compressed transaction data to the Layer 1 for security and finality.

The smallest unit of Bitcoin, equal to 0.00000001 BTC (one hundred millionth of a Bitcoin), named after Bitcoin's pseudonymous creator.

A series of 12 or 24 words that serves as the master backup for a cryptocurrency wallet, from which all private keys can be regenerated.

The practice of personally holding and controlling your cryptocurrency private keys, eliminating counterparty risk from exchanges or custodians.

An independent blockchain connected to a main chain through a two-way bridge, enabling asset transfers while operating with its own consensus rules.

Self-executing code deployed on a blockchain that automatically enforces the terms of an agreement when predetermined conditions are met, without intermediaries.

A blockchain that supports programmable smart contracts, enabling developers to build decentralized applications and financial protocols.

The potential for financial loss due to bugs, vulnerabilities, or exploits in smart contract code that can be triggered intentionally or accidentally.

A backward-compatible blockchain protocol upgrade where old nodes still accept blocks from new nodes, avoiding a permanent chain split.

A non-transferable blockchain token permanently tied to a specific wallet, used for reputation, credentials, and identity attestations.

A parallel blockchain network used for testing and development, where tokens have no real value and developers can experiment without financial risk.

A digital asset created on an existing blockchain (like Ethereum) using smart contracts, as distinct from coins which have their own native blockchain.

A set of rules and interfaces that define how tokens are created and function on a blockchain, ensuring interoperability across wallets and applications.

The process of representing real-world or digital assets as blockchain tokens, enabling fractional ownership, programmability, and 24/7 trading.

The economic design and structure of a cryptocurrency token, including supply schedule, distribution, utility, incentives, and value accrual mechanisms.

The cost paid by users to have their transactions processed and included in a block by miners or validators.

A node in a proof-of-stake network that locks up cryptocurrency as collateral to participate in block production and transaction validation, earning rewards for honest behavior.

The group of nodes responsible for validating transactions and producing blocks in a Proof-of-Stake blockchain, determining the network's decentralization.

Software or hardware that stores cryptocurrency private keys and enables users to send, receive, and manage their digital assets.

A cryptographic method that proves a statement is true without revealing any information beyond the truth of the statement itself.