What is Ethereum Gas?

On Ethereum, “Gas” refers to a unit of measurement for the amount of computation power required to execute specific operations on the network. It is a fee or a pricing value needed for a successful transaction or execution of a contract on the Ethereum Blockchain platform. It is priced in small fractions of ether (ETH) popularly termed as gwei and a few times also known as nanoeth of the gas. 
 

The appropriate gas fee is determined by the supply and demand amongst the network miners, who can decline the transaction process in case the gas fee fails to meet the threshold. The Ethereum Gas also defines a term called Gas Limit meaning, the maximum amount of gas or energy that can be spent on a transaction. 

Why Ethereum Needs Gas?

Gas can be thought of as the oxygen needed for Ethereum to remain alive. Similar to our own human life-supporting element, Ether gas is used in different ways to facilitate and expedite transactions on the Ethereum network.