Planet Earth rotates around its axis. The ends of this axis are known as the planet's two poles. Of course, there is no actual axis inside the planet, but the invisible axis can be imagined. The globe on the right simulates Earth's invisible axis with an axis made out of metal.

A day is the time during which planet Earth rotates completely around its axis. During this time, one half of the Earth faces both toward the Sun (day) and away from it (night). 

A day lasts for approximately 24 hours. The lengths of the light and dark parts of the day vary between different times of the year. 

The Sun does not actually rise during the mornings. Instead, the Earth only rotates so that one part of it faces the Sun. This makes it seem like the Sun rises from the horizon. 

Where is it day and night now?