gas fee

A gas fee is the small payment you make to have the network run your transaction or smart-contract call. Every action on a blockchain, sending coins, swapping tokens, minting a collectible, asks thousands of machines to do work and store the result, and that effort is not free. 'Gas' is simply the unit that measures how much work an action takes, much like a taxi meter measures distance: a quick payment costs little gas, while a heavy operation that touches lots of data costs a lot. You pay for the gas your action uses, in the network's native coin.

Two things set the final fee. The first is how much gas the work consumes, which depends on how complex the action is. The second is the price you offer per unit of gas, which rises and falls with demand: when many people want their transactions processed at once, the network gets congested and people offer more to be picked sooner, like surge pricing when everyone hails a ride during a downpour. The operators who add transactions to the chain tend to choose the ones offering more, so a higher offer usually means a faster confirmation, and a lower one means a longer wait.

Gas fees matter for two reasons. They reward the people who run the network and keep it secure, and they act as a natural brake against spam and runaway programs, since wasting the network's effort costs real money and a contract that exhausts its gas is simply stopped. For everyday users, fees are why a busy moment can be expensive and why much of the push toward faster, layered networks is aimed at making each action cost less.