What is Gas
Gas is the unit used to measure the level of computing power consumed to execute an ETH transaction or a smart contract utilizing Ethereum Virtual Machine (EVM). The gas price is the fee charged to conduct a contract or verify transactions on the Ethereum network. Gas prices are charged in fractions of Ether, gwei, and vary depending on how resource consuming the transaction is.
The price also changes, depending on how crowded the network is, based on the level of supply and demand.