Định Nghĩa và Ý Nghĩa của "smoke signal"

What is a "smoke signal"?

A smoke signal is a method of communication that uses smoke from a fire to send messages over long distances. By controlling the size, shape, or number of smoke puffs, simple messages can be conveyed to others who are far away. Smoke signals were commonly used by indigenous peoples, military groups, and communities in remote areas before modern communication systems existed. They are often associated with emergency alerts or basic signals due to their visibility and ability to cover large distances, especially in open areas.