The Sun appears each and every day due to the rotation of the Earth. It rises in the East and sets in the West. Because the Earth is a sphere, however, the times of sunrise and sunset vary depending on where you live in the world.
During the day the sky appears to be blue, this is because the sunlight is scattered by the small particles in the atmosphere, and blue light is scattered more than red light due to its shorter wavelength. This scattering of light can occur at all parts of the electromagnetic spectrum and is called Rayleigh scattering. Sunrise and sunset look redder as the path the light takes from the Sun passes through much more of our atmosphere, so the blue light is scattered so much we can't see it, and the longer wavelengths (redder light) appear much more strongly.
The following interactive tools allow you to find out when the sun will rise and set where you live: