A daemon is a background process in computing that runs independently of user interaction. It performs tasks such as managing system resources, handling network requests, or scheduling jobs. Daemons are essential for the smooth operation of operating systems like Linux and Unix, where they help maintain system performance and reliability. Typically, daemons start when the system boots and continue running until the system shuts down. They often have names that end with the letter "d," such as httpd for web servers or sshd for secure shell access. This naming convention helps identify their purpose and function within the system.