Are the Earth's seasons caused by the differences in the distance from the Sun throughout the year or the tilt of the Earth's axis?

Earth's tilted axis causes the seasons. Throughout the year, different parts of Earth receive the Sun's most direct rays. So, when the North Pole tilts toward the Sun, it's summer in the Northern Hemisphere. And when the South Pole tilts toward the Sun, it's winter in the Northern Hemisphere.

telophase and anaphase