In looking at the process listing on a linux server, an administrator may see a process listed as “sshd: root@notty”. An administrator, even a seasoned one, may immediately wonder “what is this ‘notty’ host?” and start down the path of trying to determine what host that is.
However, sit back and take a deep breath: “notty” means “NO TTY”. In other words, there is no TTY associated to the process, which means that the process was initiated remotely. In this case, a non-interactive process was initiated remotely over SSH.