The name itself was not chosen by accident. In fact, gas is similar to gasoline, as the energy source of the car, to ensure the normal running of the car. Gas on Ethernet "refuels" trading behavior, allowing users to perform different operations.
Every operation on the Ethereum blockchain, or exactly every operation on the Ethereum Virtual Machine (EVM), has a corresponding gas overhead. For example, three gases are needed; Add two numbers; It will cost 400 petrol; Obtain the account balance; It takes 2 1000 gas to send a transaction.
Smart contracts usually include multiple operations, which add up to hundreds of thousands of gas.
Interestingly, the gas price itself can't tell us how much we need to pay in a certain transaction. To calculate the transaction cost, the gas price must be multiplied by the gas price.
The price unit of gas is gwei, gwei is less than ETH, and 1 gwei is equal to 0.0000000 1 ETH. We can imagine their relationship as cents and dollars.