An orphan block is a correctly or incorrectly formed block that the network ultimately rejected and did not include in the main chain. It does not make it into the blockchain's overall transaction history.

An output is the part of a Bitcoin transaction that sets the recipient's address and the transfer amount. A single transaction can have several outputs at once: for different recipients and to return change to the sender.

A block reward is the payment a miner receives for a successfully created block of transactions added to the blockchain. It consists of new coins and transaction fees.

Gas is a unit measuring the computing resources needed to perform operations in the Ethereum network. The more complex a transaction, the more gas it consumes and the higher the resulting fee for processing it.

The genesis block is the very first block in a blockchain, from which the network's history begins. It lays the foundation for all subsequent blocks and effectively marks the birth of a cryptocurrency.