Node
A computer connected to a blockchain network that stores a copy of the ledger and validates transactions according to the protocol's rules. The more independent nodes there are, the more resilient and decentralized the network.
See also
Public key
A cryptographic key from which a wallet address is derived to receive funds. Unlike a private key, it can be safely shared with others — similar to a bank account number.
Seed phrase
A set of 12–24 words from which all of a wallet's private keys can be restored. It is the single most important thing to protect: anyone who knows your seed phrase can take full control of your funds.
Mining
The process of verifying transactions and creating new blocks in Proof-of-Work networks, such as Bitcoin. Miners solve complex computational puzzles and are rewarded with cryptocurrency.
Smart contract
A program that automatically executes on the blockchain once predefined conditions are met, without intermediaries. It powers most DeFi, NFT, and DAO applications.
Gas fee
The fee paid for executing a transaction or smart contract on a blockchain network such as Ethereum. The gas amount depends on network congestion — the busier the network, the more expensive a transaction becomes.
Gwei
A tiny denomination of ether (ETH) commonly used to express gas fees. One ETH equals one billion gwei.