Seasonal variation refers to the changes in weather, temperature, and daylight that occur throughout the year due to the tilt of the Earth's axis. This tilt causes different parts of the Earth to receive varying amounts of sunlight at different times, leading to the four distinct seasons: spring, summer, autumn, and winter. Each season has its own characteristics, such as warmer temperatures in summer and colder conditions in winter. These seasonal changes can significantly impact ecosystems, agriculture, and human activities. For example, many plants and animals have adapted their life cycles to align with the seasons, such as flowering in spring or hibernating in winter. Additionally, farmers often plan their planting and harvesting schedules based on seasonal patterns to optimize crop yields.