. "https://en.wikipedia.org/wiki/Signal" . . "signal" . . "An information content entity that is an input or output in a process at the boundary of a system. The signal is sent or received via ports of the system. The signal conveys information about the behavior or attributes of some phenomenon. [Allotrope]" . . "An information content entry that is an input or output in a process at the boundary of a system. The signal is sent or received via ports of the system. [Allotrope]" . "signal" .