'Gas' is a term specific to the Ethereum blockchain platform, though it's used in other blockchain ecosystems too. In the simplest sense, Gas in Ethereum represents a measure of computational effort required to execute operations on the platform. Essentially, 'Gas' is the 'fuel' that powers activities on the Ethereum network.
Whenever a transaction occurs on the Ethereum network, including smart contracts (which are automated contracts that execute transactions once certain conditions are met), these operations require some resources to process them. This resource is 'Gas.' 'Gas' is used as a way to allocate resources on the Ethereum network. The more complex the transaction, the more 'Gas' it requires to execute.
The primary purpose of 'Gas' is to ensure that transactions are processed efficiently. 'Gas' helps to:
While 'Gas' is the unit of computation, it isn't a form of cryptocurrency itself. The 'Gas' used in a transaction is converted into Ether (ETH), the actual cryptocurrency of the Ethereum platform, to reward miners for their work. The user initiating a transaction will set a 'Gas price', which is the amount of Ether they're willing to pay for each unit of 'Gas' consumed. The higher the 'Gas price', the more incentive miners have to include your transaction in a block, potentially making it faster.