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.
See also
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.
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.
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.
Altcoin
Any cryptocurrency other than Bitcoin. The term covers thousands of projects — from Ethereum and Solana to small niche tokens.