User: Why do we have seasons, and what are they?
Assistant: As the earth spins on its axis, producing night and day, it also moves about the sun in an elliptical (elongated circle) orbit that requires about 365 1/4 days to complete. The earth's spin axis is tilted with respect to its orbital plane. This is what causes the seasons.

There are four primary seasons: Spring, Summer, Autumn & Winter. The start dates of the seasons themselves are different depending on what hemisphere you're located in. Spring & Summer are the warmer seasons. Autumn is typically mild, and Winter is the coldest season of the year.