Gas

Gas generally refers to the cost associated with a transaction that is sent on-chain, or at times, off-chain. The fees don't get sent a company's balance or revenue sheet, ideally, but rather get distributed by a variety of pre determined means, including examples like mining rewards.

On Ethereum the gas is denominated in GWEI.

'Gas limit' is the most you will spend trying to see your confirmation go through. Also can be limited by gas 'slippage'.

I need gas to buy something?

I would have minted some with you, but gas fees were too high to transfer any Eth over. I didn't have enough to make it worth it.