While the Sun is a star, we don't see it at night because:

* It's the source of our daylight. The Sun is so bright that it overwhelms the light from other stars during the day.

* Earth's rotation. The Earth spins, causing day and night. When one side of the Earth faces the Sun (daytime), the other side faces away (nighttime).

Let me know if you'd like to learn more about stars or the solar system!