Glossary
Gas
The unit that measures the computational work of an Ethereum transaction. The fee paid equals gas used × gas price (in gwei).
Every opcode in the EVM costs a fixed amount of gas. The gas a transaction consumes is the sum of opcode costs along the execution path, capped by the gas limit the sender sets.
The fee the sender pays is gas used × gas price, where gas price
is denominated in gwei (10^-9 ETH). Pricing computation this way
keeps the chain from being trivially DoSed: a transaction that runs
forever simply burns through its gas limit and reverts.