Gas

In the previous section, it was mentioned that fees are paid using Ether for any execution that changes state in Ethereum. Ether is traded on public exchanges and its price fluctuates daily. If Ether is used for paying fees, then the cost of using the same service could be very high on certain days and low on other days. People will wait for the price of Ether to fall to execute their transactions. This is not ideal for a platformsuch as Ethereum. Gas helps in alleviating this problem. Gas is the internal currency of Ethereum. The execution and resource utilization cost is predetermined in Ethereum in terms of gas units. This is also known as gas cost. There is also gas price that can be adjusted to a lower price when the price of Ether increases and a higher price when the price of Ether decreases. For example, to invoke a function in a contract that modifies a string will cost gas, which is predetermined, and users should pay in terms of gas to ensure smooth execution of this transaction.