DEFINITION of Gwei (Ethereum)
Gwei is a denomination of ether (ETH), the cryptocoin used on the the Ethereum network.
1 Ether = 1,000,000,000 Gwei (109)
BREAKING DOWN Gwei (Ethereum)
Similar to the various small-value coins that are in circulation for real-world fiat currency like the nickel, dime and penny, several denominations have become popular in the cryptocurrency world to refer to the various fractional values of a particular token.
With ether valuations shooting through the roof recently, transaction sizes have become smaller. Say, if 1 ETH = 800 USD, then one needs to spend only a fraction of an ether (0.0025 ETH) for an equivalent of 2 USD. Other fractional costs, like the mining fee, may be even smaller in value, which makes it difficult to quote the lengthy fractional value (like 0.000034243 ETH).
New digital currency denominations are becoming popular that help to correctly denote the smaller transactions which may appear like a very lengthy fraction in terms of ether, but a high value when converted to U.S. dollars or other fiat currency.
Gwei is also called shannon, nanoether, or simply nano, to denote the ninth power of the fractional ether. (See also, Wei Definition.)