Gas Limit

The maximum amount of computational work (measured in gas units) that a user is willing to pay for a transaction to be processed on a blockchain. If a transaction requires more gas than the specified limit, it fails and the gas is still consumed. Simple ETH transfers require 21,000 gas, while complex smart contract interactions can require millions. Setting the gas limit too low causes out-of-gas errors; setting it too high wastes funds if the transaction fails.