Everything in this universe needs some energy, force, or effort to work. That effort can be of a different type in different cases. Similarly, in ICO etherium, every work is done by the utilization of some computational effort. That computational effort is etherium gas. In etherium, every operation that is performed from small transaction to execution of big operation the gas is used, e.g., Cars, vehicles, and airplanes use some fuel to work. When the fuel is provided, those large machines start their work. Similarly in etherium gas works as fuel whenever the system is ordered to perform any action the gas consume
Etherium gas has its unit which is known as Gwei, which has the value of .000000001 ETH. Suppose you can relate Gwei with cents since a cent is equal to 0.01 of the dollar. For every transaction, you will make. First, you have to set a proper price or fee that you will pay to perform your transaction. When you are sending etherium to somebody, at the same time, millions of transactions are being performed in the etherium block, and the transactions are then sent to the memo pool for verification. Miners verify them, and miners confirm the surety of not being a scam, so there is a queue of non-verified transactions which are being verified so that they can be performed. Hence, the miners always prefer those transactions first, which pay more gas. That’s why you set the fee. So if you pay a higher fee, your transaction will be done more quickly, and if you pay a lower fee, it will be late. In easy terms, we can say it’s all about time-saving
Basically, in normal life, we can take the examples of the bank that the bankers are responsible for carrying out all the transactions similarly n etherium all the transactions are carried out by miners for which they get paid. There are specific sites that calculate the gas limit for work done. So it depends upon the work and the time. Suppose we require the transaction to take place urgently, then we should pay the gas fee a bit higher, and if it’s some casual work that can be done anytime, we should pay a normal gas fee. The statistics of the gas price get changed every second.
But the gas fee is always paid in ETH. It can’t be paid with the coin or the currency you are sending, so you must have some amount of ETH in your wallet. The gas limit is the highest amount of gas that you pay for a service transaction, and the standard gas limit is set between 21000. The minimum gas limit is 21000. It only ensures the delivery of the transaction, but it takes a lot of time. When we send Ether to another address, it takes a minimum amount of gas because this process is a very little operation to be performed by miners. When sending Ether to another address with some added metadata, it takes some gas because we are adding some metadata. The most expensive gas fee is caused when we are publishing a complex smart contract. Sometimes people keep gas prices too low that transaction fails. It eventually ends up having a gas price higher than what you selected, resulting in transaction error.
This scheme is important because it protects the network against attacks. When you pay for the gas fee, it goes to the miners who then protect the network against DDOS, so a much you pay, it goes for the betterment of etherium.