What causes the seasons on Earth?

We have four seasons because our planet is tilted at an angle. The season depends on whether we are tilted toward or away from the Sun. (Seasons have nothing to do with how close Earth is to the Sun. During summer, Earth is not closer to the Sun. In fact, it is farther away.)

In spring, the northern half of Earth is tilted toward the Sun. The days start to become longer and warmer. By the middle of summer, the Sun’s rays are shining directly on the northern hemisphere. The days are long and hot.

The reverse happens in winter. Then, the north is tilted away from the Sun. So, the days are short and dark.
When it is summer in the northern half of the Earth, it is winter in the southern half. This means that Christmas comes in the middle of summer in southern countries such as Argentina and New Zealand. We wonder if Santa arrives in sunglasses and shorts?