When our side of the earth is facing the sun, is it day or night?
The side of something is a position to the left or right of it, rather than in front of it, behind it, or on it. 一侧
If someone or something faces a particular thing, person, or direction, they are positioned opposite them or are looking in that direction. 面向
Facts about days and nights
The Earth rotates on its own axis from west to east in 24 hours and around the Sun in a year. That is why the Sun appears to rise from the East and set in the West. Only half of the globe is facing the Sun at any one time, but because the Earth rotates in 24 hours all of the Earth has faced the Sun during this time. In the part lit by the Sun, it is day. The other side of the globe is in the shadow and does not receive the light of the Sun. In this part of the Earth, it is night.
As the axis of the Earth is tilted, days and nights are not equal: day and night do not last 12 hours each but their length changes over the year as the Earth rotates around the Sun and its position changes.