How is "glide ratio" defined?

Glide ratio is defined as the ratio of the horizontal distance traveled to the vertical distance lost during a glide descent. It provides a measure of how efficiently an aircraft can travel forward while descending without power. For example, a glide ratio of 10:1 means that for every unit of altitude lost, the aircraft can travel 10 units forward. This concept is crucial for understanding flight performance, particularly in situations where engine failure may occur, allowing pilots to plan for a safe landing by maximizing distance with minimal altitude loss. Other options such as the speed during a glide, the time spent gliding, or the maximum height don't effectively convey the specific relationship that glide ratio represents.