Explain the Difference between “Gas” and “Gas Limit” in a Transaction

"Gas" refers to the computational effort required to execute an operation on the blockchain, and its cost is measured in the blockchain's native currency. "Gas limit" is the maximum amount of gas a user is willing to spend on a transaction.

Setting a gas limit prevents users from spending excessive funds on a faulty or complex transaction. If the operation costs less than the limit, the user is refunded the difference.