Gas Fee
Quick definition
The network fee paid to process a transaction on smart-contract blockchains like Ethereum.
Gas is the fee that pays validators to execute your transaction on chains like Ethereum. It rises when the network is busy and falls when it's quiet — the same swap can cost cents or tens of dollars depending on congestion.
Bitcoin has its own network fees but the word 'gas' usually refers to smart-contract chains. If you use a DEX, you need the chain's native coin to pay gas.
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