The Sun appears visible during the daytime because of its proximity to Earth and the scattering of sunlight by the Earth's atmosphere. While the Sun is indeed a star, it is significantly closer to us compared to any other star in the universe. Its distance allows it to appear much larger and brighter in our sky compared to other stars.
During the day, the Earth's atmosphere scatters sunlight in all directions. This scattering is caused by the molecules and tiny particles in the atmosphere. The blue light from the Sun is scattered more than other colors due to its shorter wavelength, which is why the sky appears blue.
The scattered light from the Sun illuminates the entire sky, making it bright and obscuring the view of most stars. The stars we see at night are much farther away, and their light is relatively dim compared to the Sun. When the Sun sets and the sky darkens, the scattered sunlight diminishes, allowing the faint light of more distant stars to become visible.
It's important to note that even though the Sun appears larger and brighter than other stars, it is still a star like them. It emits energy through nuclear fusion processes occurring in its core, just like other stars in the universe. However, due to its proximity, the Sun's intense light and heat make it the dominant celestial object in our daytime sky.