Final answer:
The change in seasons is primarily due to the tilt of the Earth's axis and its revolution around the Sun.
Step-by-step explanation:
The change in seasons is primarily due to the tilt of the Earth's axis, which is about 23.5 degrees. As the Earth revolves around the Sun, different parts of the planet receive varying amounts of sunlight, leading to the different seasons. When one hemisphere is tilted towards the Sun, it experiences summer, while the other hemisphere is tilted away and experiences winter. The rotation of the Earth also plays a role in causing the change in seasons, as it affects the length of daylight hours in a day.