Gas measures how much computational work a transaction needs. Simple transfers cost less gas than complex contract interactions. The total fee is roughly gas used × gas price (plus priority tips on EIP-1559 networks).
When gas spikes, mints and bridges get expensive fast. Checking a multi-chain gas tracker before you sign helps you wait, switch networks, or resize the action.
Gas is not the same as the token amount you send. You can transfer 1 ETH and still pay a separate gas fee in ETH (or the chain’s native asset).