Ether is the currency of the Ethereum network. It is required to power the Ethereum Virtual Machine (the name that has been given to the decentralized world computer). The amount of Ether needed for a smart contract is dependant on the amount of processing power and complexity of the digital agreement. Simply transferring Ether is one of the simplest executions and would not cost a lot. Programming an entire homeowner’s insurance agreement into a smart contract might cost many Ether because there are so many possible events that need to be addressed.