The change in seasons on the earth occurs because—

Seasons on Earth occur because the Earth's axis of rotation is tilted at approximately 23.5° with respect to the plane of its orbit around the Sun. This tilt causes different parts of the Earth to receive varying amounts of direct sunlight throughout the year. When the Northern Hemisphere is tilted toward the Sun, it experiences summer while the Southern Hemisphere has winter, and vice versa. The varying distance from the Sun is negligible and not the cause of seasons.