The tilt of the Earth's equator with respect to the orbital plane and the direction in which the Earth's rotation axis points in space as it orbits around the Sun causes the Earth to experience seasons. This is because the Earth's rotation axis is tilted at an angle of approximately 23.5 degrees relative to its orbital plane, which means that different parts of the Earth receive different amounts of sunlight at different times of the year.
When the Earth is tilted so that the northern hemisphere is pointing towards the Sun, the northern hemisphere experiences summer, while the southern hemisphere experiences winter. When the Earth is tilted so that the southern hemisphere is pointing towards the Sun, the southern hemisphere experiences summer, while the northern hemisphere experiences winter.
The tilt of the Earth's axis also causes the length of the day and the angle of the Sun's rays to change throughout the year, leading to changes in temperature, weather patterns, and other environmental conditions. Overall, the Earth's tilt is a fundamental factor that influences many aspects of life on Earth.