Other Parts to Ethereum

Computers need to be able to calculate, store data, and communicate. For Ethereum to realise its vision as an unstoppable, censorship resistant, self-sustaining, decentralised, ‘world’ computer, it needs to be able to do those three things in an efficient and robust way. The Ethereum Virtual
Machine is just one component of the whole, the element which does the decentralised calculations.

Swarm is another component. This is for peer-to-peer file sharing, similar to BitTorrent, but incentivised with micropayments of ETH. Files are split into chunks, distributed and stored with participating volunteers.These nodes that store and serve the chunks are compensated with ETH
from those storing and retrieving the data. Whisper is an encrypted messaging protocol that allows nodes to send messages directly to each other in a secure way and that also hides the sender and receiver from third party snoopers.

Smart contracts mean different things depending on the blockchain platform. Ethereum smart contracts are short computer programs that are stored on Ethereum’s blockchain, replicated across all the nodes, and are available for anyone to inspect. There are two steps that are performed separately: uploading the smart contract to Ethereum’s blockchain; making the smart contract run.

You upload a smart contract by sending the code to miners in a special transaction. If the transaction is successfully processed, the smart contract will then exist at a specific address on Ethereum’s blockchain. You may then make it run by creating a transaction that says ‘Please run the smart contract found at address x’.

Once a contract has been uploaded, it behaves a bit like a jukebox. When you want to run it, you create a transaction pointing to the contract and supply whatever information the contract expects. You pay gas to the miner to run it. As part of the mining process, each miner will execute the
transaction, which involves running the smart contract.

The miner who successfully wins the proof-of-work challenge will publish the winning block to the rest of the network. The other nodes will validate the block, add the block to their own blockchains, and process the transactions, including running the smart contracts. This is how Ethereum’s blockchain gets updated, and how the state of the EVMs on each node’s machine is synchronised.
Ethereum smart contracts are described, ‘Turing complete’. This means that they are fully functional and can perform any computation that can be done in any other programming language.