Why do we have seasons on Earth?

Explanation

(i) The seasons in the Earth arise due to the rotation of Earth around the Sun with `23.5^(@)` tilt.
(ii) Due to this `23.5^(@)` tlit, when the northern part of Earth is father to the Sun, the southern part is nearer to the Sun.
(iii) So when it is summer in the northern hemisphere, the southern himisphere experience winter.