Gas fees are the cost of running a transaction on the Ethereum network. Gas measures how much work a transaction asks Ethereum to do.

A transaction pays for gas in Ether. The base fee is the required part of the fee and gets burned, which means it is removed from circulation. The priority fee is an optional tip to the validator that includes the transaction. A higher tip can make a transaction more attractive to include when blocks are busy.

The more complex the transaction, the more gas units it uses. The busier the network, the higher the gas price for each unit. Gas price is usually shown in Gwei, a small unit of Ether, so the gas cost is gas units multiplied by gas price.