Recording on the Blockchain

While all the nodes in Ethereum are equal peers, some of them are operated by miners and are feeding transactions and blocks to mining farms, which are computers with high-performance graphics processing units (GPUs). The mining computers add transactions to a candidate block and attempt to find a proof of work that makes the candidate block valid. We will discuss this in more detail in [consensus].

Without going into too much detail, valid transactions will eventually be included in a block of transactions and, thus, recorded in the Ethereum blockchain. Once mined into a block, transactions also modify the state of the Ethereum singleton, either by modifying the balance of an account (in the case of a simple payment) or by invoking contracts that change their internal state. These changes are recorded alongside the transaction, in the form of a transaction receipt, which may also include events. We will examine all this in much more detail in [evm_chapter].

A transaction that has completed its journey from creation through signing by an EOA, propagation, and finally mining has changed the state of the singleton and left an indelible mark on the blockchain.