We have seasons because the Earth is tilted on its axis (about 23.5 degrees) and it orbits around the Sun.

When the North Pole is tilted toward the Sun, the Northern Hemisphere (like India, Europe, USA) gets more sunlight—that’s summer there.

At the same time, the Southern Hemisphere (like Australia, South Africa) is tilted away from the Sun and gets less sunlight, so it's winter there.

As Earth keeps moving around the Sun, this tilt causes spring, summer, autumn, and winter at different times in different places.

So, the tilt and the movement around the Sun together make our seasons