What are the three basic causes of seasons?

The three basic causes of seasons are the tilt of the Earth's axis, its orbit around the Sun, and the varying angle of sunlight that reaches different parts of the Earth. The Earth's axial tilt of about 23.5 degrees causes different hemispheres to receive varying amounts of sunlight throughout the year. As the Earth orbits the Sun, this tilt results in the changing seasons—summer, winter, spring, and fall—depending on the hemisphere's orientation towards or away from the Sun. This combination of tilt and orbital position influences temperature and daylight duration, leading to seasonal variations.