Why does summer occur in the northern atmosphere when winter occurs in the southern atmosphere?

Summer occurs in the northern hemisphere while winter occurs in the Southern Hemisphere due to the tilt of the Earth's axis. During the northern hemisphere's summer, it is tilted toward the Sun, receiving more direct sunlight and longer daylight hours. Conversely, the southern hemisphere is tilted away from the Sun, resulting in less direct sunlight and shorter days, thus experiencing winter. This axial tilt is responsible for the seasonal variations as the Earth orbits the Sun.