The Lift-to-Drag Ratio (L/D ratio) is a measure used in aerodynamics to compare the lift generated by an aircraft to the drag it experiences. A higher L/D ratio indicates that an aircraft can generate more lift for each unit of drag, which is desirable for efficient flight. This ratio is crucial for aircraft design, as it affects fuel efficiency, range, and overall performance. In practical terms, a glider typically has a high L/D ratio, allowing it to soar for long distances without an engine. In contrast, a commercial jet like the Boeing 747 aims for a balanced L/D ratio to optimize both speed and fuel consumption during flight.