Fog signals are sound signals used by ships and coastal installations to communicate their presence in low visibility conditions, such as fog. These signals help prevent collisions by alerting nearby vessels to their location. Common types of fog signals include horns, bells, and whistles, which produce distinct sounds that can be heard over long distances. In addition to maritime use, fog signals are also employed in railways to warn trains of obstacles or other trains ahead. The use of fog signals is crucial for safety in both maritime navigation and rail transport, ensuring that operators can make informed decisions in challenging weather conditions.