On this image, we can see the Earth being tilted away by 23.5 degrees from the Sun. This tilting puts the Northern Hemisphere in a situation where it is the one that is tilted away from the Sun, thus it will receive less sunlight, as well as less direct sunlight. That will cause lower temperatures on the Northern Hemisphere, thus the winter season will start, and it will last for around three months, at least at the mid-latitude zones. On the other side, the Southern Hemisphere is more exposed to the Sun during this tilting, so t receives more sunlight, and more direct sunlight, resulting in summer in this half of the planet.
