The main difference of the Ethereum network consists available the decentral virtual machine (EVM) which allows launching any program or the smart contract. That is Ethereum was created not as currency for the translations and as the platform for execution of applications.
The Ethereum network is generally used for execution of the following operations: transfer of ETH and also creation and execution of smart contracts. It is necessary to pay for each of these operations. At this stage we need Gas. The operation is more difficult, the more it is necessary to give Gas. So, the creation of the smart contract requires more “gas”, than for transfer of ETH. After switching on of transaction in the unit the amount of gas consumed by the contract is transferred to ETH and written off in favor of the miner.
The quantity of Gas is automatically determined depending on the complexity of operation. But the user can regulate the price of “gas” in a certain range * gwei where 1 ETH = 1000000000 gwei. It is obvious that than the high price of Gas, subjects quicker transaction will get to the unit (miners select expensive transactions more willingly).
Thus, one may say, that Gas on the Ethereum network is the means of execution of operations paying computing resources of miners.
The primary benefit of Gas before the normal commissions consists of flexibility and convenience of its use (especially in case of programs and smart contracts).
* Relevant limits can be found on MyEtherWallet or in an official purse. In the same place, it is possible to test all opportunities of the Ethereum network in practice.