Fiat
Traditional government-issued currency not backed by a physical commodity, such as the US dollar, euro, or Czech koruna — as opposed to cryptocurrency.
See also
Nonce
A number used once, which miners search for when mining a block in Proof-of-Work networks; also a counter that prevents a transaction from being replayed on an account.
Block explorer
A web service that lets you browse blocks, transactions, and addresses on a blockchain in real time (for example, Etherscan for Ethereum).
Satoshi
The smallest unit of Bitcoin, equal to one hundred-millionth (0.00000001) of a BTC. Named after Bitcoin's creator.
Exchange
A platform for buying, selling, and trading cryptocurrencies. It can be centralized (CEX) or decentralized (DEX).
Genesis block
The very first block in a blockchain, from which the entire chain begins. Bitcoin's genesis block was created on January 3, 2009.