This is the amount paid in crypto for transacting on a particular blockchain. The gas fee is typically a fraction of the native coin of the blockchain used for a transaction. For example, Solana might charge a standard gas fee of 0.000005 SOL per transaction; this could be an NFT purchase, a token swap, or other deals. The essence of paying this fee is to reward miners or stakers (block generators) for the energy expended in maintaining the blockchain.
McDonald’s
It’s used jokingly as an alternative career to a failed NFT investment. The NFT community uses it comically as the career option to fall on