Why does the position of the constellations change over time?

In the nights when the moon is dark, the sky is clear, and standing still, you will see stars flashing in the black sky.

If you are always looking, you will see stars rising from the East, slowly gliding through the sky, gradually descending to the West, just as we see the sun rising from the East every day. In fact, it is caused by the Earth rotating from west to east.

In addition to everyday we see stars running from East to West, the moment each star starts growing the next day 4 minutes earlier than the day before. So every time the night is the same for a year, the stars we see are not the same, the locations of the constellations shift to the west. For example, the Orion we know, in early December at dusk, it rose from the East, and after three months of sunset it had set in the West. This constellation runs in the southern sky. But by the end of spring, it had set with the Sun at sunset.

Along with the changing seasons, the constellations are moving slowly to the west because the Earth is still orbiting the sun. If we could see stars during the day, we would see the Sun gradually turning east between the constellations. Each day the Sun moves one degree east, which is equivalent to twice the diameter of the Sun. So in one year the stars "moved around the year" in the sky.

In short, stars have two moving phenomena: one due to the rotation of the Earth that causes day-to-day motion, forming every night the stars rising from the east dive to the west.

The second phenomenon is due to the Earth orbiting the Sun causing a circular motion of the year, causing the constellations to appear to change according to the seasons. We should not confuse the two phenomena into one.