The apparent motion of the Sun through our sky is primarily a result of Earth's rotation on its axis and its orbit around the Sun. The Sun appears to move from east to west during the course of a day.
Earth's rotation causes the Sun to rise in the east and set in the west. As the Earth spins on its axis from west to east, different parts of the planet are exposed to sunlight at different times, creating the cycle of day and night. This rotation gives the illusion of the Sun moving across the sky.
Throughout the year, the Sun's path across the sky appears to change due to Earth's orbit around the Sun. Earth's axis is tilted relative to its orbital plane, resulting in the changing seasons. This tilt, combined with the elliptical shape of Earth's orbit, causes the Sun to appear higher or lower in the sky at different times of the year. This is why we experience variations in daylight hours and the height of the Sun in different seasons.
During the summer solstice, around June 21st in the Northern Hemisphere, the Sun reaches its highest point in the sky and appears to follow its longest and highest path. Conversely, during the winter solstice, around December 21st in the Northern Hemisphere, the Sun appears at its lowest and shortest path.
The apparent motion of the Sun through our sky is an observable phenomenon resulting from Earth's rotation and orbit around the Sun, combined with the tilt of Earth's axis.