Day and night
Most people don't really bother finding out how this happens or they just don't know this. But because i HAVE to do this as work i will tell u anyway. :)
Why does it happen?
We have day and night mainly because the Earth rotates. It spins on it's axis, which is just basically an imaginary line passing through the North and South poles. The reason why we never feel the Earth spinning is because it spins EVER so slowly. This process of the Earth spinning takes 24 hours to complete a full rotation, and that is what we call a day. This is why we get day and night.
When the Earth faces the Sun, we have day and when the Earth face against the Sun we have night.
