The amount of sunlight the Earth gets is the cause of both cycles that most people are familiar with. Every 24 hours the Earth goes through the day/night cycle. The words dawn, noon, twilight are all used to describe the daily relationship that the Earth has with the Sun. There are also words to describe the yearly relationship with the Sun. Spring, Summer, Autumn and Winter are the words to describe the yearly cycle of the Earth. These seasons are directly caused by changes in the amount of sunlight that the Earth receives.
