Ethereum has a Turing-complete platform built into it that allows the blockchain to function like a large distributed computer.
The Ethereum Virtual Machine is a part of every Ethereum client software on the blockchain, and it allows the interconnected computers to function as one processor. Distributed computation such as this is not really a new thing, but the fact that it allows all developers in Ethereum to decentralized their projects makes this one of the most revolutionary aspects of the Ethereum platform.
The Virtual Machine coordinates the efforts of many computers on the network to help things run as efficiently as possible when processing transactions, smart contracts, and calls to decentralized applications. Each node on the network can be called upon to perform the computations required of the EVM, as it’s called, and this service is one of the ways that nodes can be paid by the network, much like miners are rewarded on the Bitcoin blockchain. Each computation that a user pushes through the virtual machine has a fee associated with it, calculated as “Gas” which is in-line with Ethereum’ s analogy for Ether as “fuel” for the platform.
If the computation is more involved and takes more time than other transactions, the Gas bill goes up. The Gas must be paid in ether by the initiator of the transaction by approving a small extra amount of Ether to the transaction. The EVM can also run tests for developers without influencing the active blockchain ledger. Its Turing-completeness means that it can run all sorts of computations and applications as if it were a single very powerful computer. Decentralized applications and smart contracts are the primary reason that investors and developers support and make use of the Ethereum platform.