デーモン

In computing, a daemon (pronounced 'dee-mon') is a type of program that runs as a background process, rather than being under the direct control of an interactive user. Daemons are typically started at boot time or when a specific service is initiated and continue to run indefinitely, waiting for events to occur or performing tasks periodically. They are often used to provide services that other programs or users can access, such as web servers (e.g., Apache httpd), database servers (e.g., mysqld), or network services (e.g., sshd). The name 'daemon' originates from Greek mythology, referring to a supernatural being, and was adopted in computing to signify a process that works tirelessly in the background. Daemons are designed to be long-running and often detached from any controlling terminal, meaning they continue to execute even if the user who started them logs out. They typically perform system-level tasks, manage resources, or respond to network requests. In the context of blockchain nodes (e.g., Bitcoin Core or Geth for Ethereum), daemon processes are crucial for maintaining the network connection, validating transactions, synchronizing the blockchain ledger, and relaying information to other nodes. These daemons listen for incoming transactions and blocks, process them according to the protocol rules, and update the local copy of the distributed ledger.