All the important blockchain and cryptocurrency terms you need to know,
organized alphabetically. Click a letter to jump to that section!
A
Address
A unique string of characters that represents a destination for cryptocurrency, similar to an email address. Derived from the public key. Learn more →
Airdrop
Free distribution of tokens to wallet addresses, often used for marketing or rewarding early adopters.
Altcoin
Any cryptocurrency other than Bitcoin. Short for “alternative coin.” Examples: Ethereum, Solana, Cardano. Learn more →
ASIC
A specialized microchip designed for one specific purpose—in crypto, for mining. Learn more →
B
Bitcoin (BTC)
The first and most well-known cryptocurrency, created by Satoshi Nakamoto in 2009. Learn more →
Block
A container of transaction data in the blockchain. Each block is linked to the previous one. Learn more →
Blockchain
A distributed, decentralized digital ledger that records transactions across many computers. Learn more →
Block Explorer
A website that allows you to view all transactions, blocks, and addresses on a blockchain. Example: Etherscan for Ethereum.
Block Reward
The cryptocurrency reward given to miners/validators for successfully adding a new block. Learn more →
Bridge
A protocol that connects two different blockchains, allowing assets to move between them.
Bull Market / Bear Market
A bull market is when prices are rising. A bear market is when prices are falling. Named after how the animals attack: bulls thrust upward, bears swipe downward.
Burn
Permanently removing tokens from circulation by sending them to an inaccessible address.
C
Cold Wallet
A wallet that stores private keys offline (not connected to the internet). Learn more →
Consensus Mechanism
The method by which a blockchain network agrees on the current state of the ledger. Examples: Proof of Work, Proof of Stake. Learn more →
Cryptocurrency
A digital currency secured by cryptography, operating on a blockchain. Learn more →
Cryptography
The science of encoding and decoding information. Blockchain uses it for security and digital signatures.
D
DAO (Decentralized Autonomous Organization)
An organization governed by smart contracts and community voting rather than a central leadership.
DApp (Decentralized Application)
An application that runs on a blockchain network rather than a central server.
DeFi (Decentralized Finance)
Financial services (lending, borrowing, trading) built on blockchain, without banks or intermediaries.
Decentralized
Not controlled by a single entity. Power is distributed across many participants in the network.
Double Spending
The risk of spending the same digital currency twice. Blockchain solves this problem.
E
ERC-20
A technical standard for creating tokens on the Ethereum blockchain.
Ethereum (ETH)
A programmable blockchain platform that supports smart contracts, created by Vitalik Buterin. Learn more →
Exchange
A platform where you can buy, sell, and trade cryptocurrencies. Examples: Coinbase, Binance, Kraken.
F
Fiat Currency
Government-issued money (like USD, EUR, GBP) not backed by a physical commodity.
Fork
A change to a blockchain’s protocol. A hard fork creates a new chain (e.g., Bitcoin Cash). A soft fork is backward-compatible.
FOMO
Fear Of Missing Out – the anxiety that you’ll miss a profitable investment opportunity.
FUD
Fear, Uncertainty, and Doubt – negative information spread to drive prices down.
G
Gas
The fee paid for transactions and computations on the Ethereum network. Measured in gwei (a tiny fraction of ETH).
Genesis Block
The very first block in a blockchain (Block 0). Bitcoin’s Genesis Block was mined on January 3, 2009. Learn more →
H
Halving
An event where the block reward is cut in half, occurring roughly every 4 years for Bitcoin. Learn more →
Hash
A fixed-length string produced by a hash function. Acts as a digital fingerprint. Learn more →
Hash Rate
The total computational power being used to mine and process transactions. Measured in hashes per second.
HODL
A misspelling of “hold” that became crypto slang for holding (not selling) your crypto long-term, regardless of price drops.
Hot Wallet
A wallet connected to the internet. Convenient but less secure. Learn more →
I
ICO (Initial Coin Offering)
A fundraising method where new projects sell tokens to early investors. Popular in 2017.
Immutable
Cannot be changed or altered after being recorded. A key property of blockchain data.
K
KYC (Know Your Customer)
Identity verification required by exchanges and financial platforms to comply with regulations.
L
Layer 1
The base blockchain (e.g., Bitcoin, Ethereum). The foundation layer.
Layer 2
Solutions built on top of Layer 1 to improve speed and reduce fees. Examples: Lightning Network (Bitcoin), Polygon (Ethereum).
Ledger
A record of all transactions. In blockchain, the ledger is distributed across all nodes in the network.
Liquidity
How easily an asset can be bought or sold without significantly affecting its price.
M
Mainnet
The primary, live blockchain network where real transactions occur (as opposed to a testnet).
Mempool
The “waiting room” where unconfirmed transactions sit before being picked up by miners.
Merkle Tree
A data structure used to efficiently verify the integrity of transactions in a block.
Mining
The process of using computational power to validate transactions and create new blocks. Learn more →
Mining Pool
A group of miners who combine their computing power and share rewards. Learn more →
Minting
The process of creating new tokens or NFTs on the blockchain.
N
NFT (Non-Fungible Token)
A unique digital asset that represents ownership of something (art, music, collectibles). Unlike BTC, each NFT is one-of-a-kind.
Node
A computer that participates in the blockchain network by maintaining a copy of the ledger. Learn more →
Nonce
“Number used once” – a number miners change to try different hash outputs when mining.
O
Oracle
A service that provides real-world data to smart contracts (e.g., prices, weather). Chainlink is the most popular oracle network.
P
Peer-to-Peer (P2P)
A network where participants interact directly with each other without a central authority.
Private Key
A secret cryptographic key that proves ownership and allows you to send cryptocurrency. Learn more →
Proof of Stake (PoS)
A consensus mechanism where validators stake coins as collateral. Learn more →
Proof of Work (PoW)
A consensus mechanism where miners solve computational puzzles. Learn more →
Public Key
A cryptographic key derived from the private key. Can be shared publicly for receiving crypto. Learn more →
S
Satoshi
The smallest unit of Bitcoin: 0.00000001 BTC. Named after Bitcoin’s creator.
Satoshi Nakamoto
The pseudonymous creator of Bitcoin. Their true identity remains unknown.
Seed Phrase
A set of 12 or 24 words used to recover a cryptocurrency wallet. Learn more →
SHA-256
The cryptographic hash function used by Bitcoin. Produces a 256-bit (64-character) hash. Learn more →
Slashing
A penalty in Proof of Stake where a validator loses part of their staked coins for malicious behavior.
Smart Contract
A self-executing program stored on the blockchain that automatically enforces the terms of an agreement.
Stablecoin
A cryptocurrency designed to maintain a stable value, usually pegged to a fiat currency. Learn more →
Staking
Locking up cryptocurrency to support network operations and earn rewards in Proof of Stake systems.
T
Testnet
A test blockchain used by developers to experiment without using real money.
Token
A digital asset created on an existing blockchain (e.g., ERC-20 tokens on Ethereum). Learn more →
Transaction Fee
A small fee paid to miners/validators for processing a transaction.
TPS (Transactions Per Second)
A measure of how many transactions a blockchain can process each second.
V
Validator
A participant in a Proof of Stake network who verifies transactions and creates new blocks.
Volatility
The degree of price fluctuation. Crypto is known for being highly volatile.
W
Wallet
A tool for storing, sending, and receiving cryptocurrency. Learn more →
Whale
An individual or entity that holds a very large amount of cryptocurrency. Their buy/sell actions can influence market prices.
Whitepaper
A detailed document explaining a cryptocurrency project’s technology, purpose, and vision. Bitcoin’s whitepaper was published in 2008. Learn more →
Web3
The vision of a decentralized internet built on blockchain technology, where users own their data and digital assets.