Why do Seasons Change - What Causes the Change in Seasons?

Why do Seasons Change - What Causes the Change in Seasons?

People since ancient times considered the change of seasons.

Why is it hot in summer and cold in winter?

Why the days get longer in the spring?

Why during the winter the nights are longer?

We all know that the Earth revolves around the sun, and at the same time around its axis.
If the Earth's axis (the imaginary line that passes through the North and South Pole) was at 90 degrees to the Earth's orbit around the sun, than we would have no distinct seasons, and all the days of the year would have the same length.
But the Earth's axis is slightly tilted and this is because on the Earth influence various forces.
One is the attraction toward the sun, the other is attraction of the moon, and the third is the Earth’s movement around its axis.
Due to the action of these forces, the Earth revolves around the sun in an inclined position. The Earth is always throughout the year in this position, so that the Earth's axis always lies in the same direction - toward the North Star.

This means that the North Pole one part of the year faces the Sun, and the second part of the year away from the Sun. Because of this tilt, the sun's rays fall directly on the Earth, sometimes north of the Equator, sometimes on the Equator, and sometimes south of the Equator. The angle in which the sun rays fall on Earth is in strict correlation with the different seasons in different parts of the world.
When the northern hemisphere faces the sun, in the countries north of the Equator is summer, and in the countries south of the Equator winter.
When the sun's rays fall vertically to the southern hemisphere, it is summer there, and in the northern hemisphere winter.
The year has two days when day and night are equal around the world.
These are the autumn equinox on 23 September and the spring equinox on 21 March.