Altcoin
Any cryptocurrency other than Bitcoin. The term covers thousands of projects — from Ethereum and Solana to small niche tokens.
See also
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.
Stablecoin
A cryptocurrency pegged to a stable asset, most often the US dollar. It is used to avoid volatility and to settle transactions within the crypto market (examples: USDT, USDC).
DeFi
Decentralized Finance — an ecosystem of blockchain applications (lending, trading, insurance) that operates without banks or other traditional intermediaries.
NFT
A Non-Fungible Token — a unique blockchain record that certifies ownership of a specific digital or physical item, such as artwork, music, or a ticket.