The Sun is going down. This is called ____.

What is the difference between day and night? The Sun shines during the day. We cannot see the Sun at night. So it is dark at night. As well as changing the weather the parts of the year, or seasons, affect the length of days. In winter days are shorter and nights longer, but in summer days are longer and nights shorter. How do the seasons change the length of the days as well as the weather? In science you will have found out about the Sun and about day and night. What are the different parts of the day called?