Comment by rob74
20 days ago
"Semaphore" is (old) Greek and means "sign (sema) bearer (phore)", and actually the meaning in railways and computing is more or less the same: in computing, a semaphore signals if a resource is in use; in railways, the resource is a segment of a railway line, and the user is a train.
It does the same role in plain roads between pedestrians, cars and similar vehicles.