The tilt angle refers to the angle at which an object is inclined relative to a reference plane, often the horizontal. In the context of Earth, the tilt angle is crucial as it affects the planet's climate and seasons. Earth's axial tilt is approximately 23.5 degrees, which leads to variations in sunlight received at different latitudes throughout the year. In engineering and physics, the tilt angle can influence the performance of structures and devices. For example, in solar panel installations, adjusting the tilt angle can optimize energy capture from the sun, enhancing the efficiency of solar energy systems.