Gas fee is required to successfully conduct a transaction or execute a contract on the blockchain
On the Ethereum blockchain, gas refers to the cost necessary to perform a transaction on the network.
In essence, gas fees are paid in Ethereum’s native currency. Gas prices are denoted in Gwei, which itself is a denomination of ETH – each Gwei is equal to 0.000000001 ETH (10-9 ETH). For example, instead of saying that your gas costs 0.000000001 Ether, you can say your gas costs 1 Gwei.
For basic ETH transactions, a standard gas limit is 21,000. So for example, let’s consider a hypothetical generic transaction sent when the gas price is 100 gwei. We can compute this transaction’s cost by multiplying 21,000 (gas limit) x 100 (gas price) x 0.000000001 (gwei denomination), with the result being 0.0021 ETH.
Gas limits for ERC-20 token transfers can range from 25,000 to as high as 500,000.
If the gas limit exceeds your ETH balance, the transactions will not be initiated and an error pop-up will appear.