Question

what difference would there be if the axis of the earth was not tilted by twenty three half degree​

Answer 1

That's logical, but not the case, for Earth. Instead, Earth has seasons because our planet's axis of rotation is tilted at an angle of 23.5 degrees relative to our orbital plane – the plane of Earth's orbit around the sun. The tilt in the axis of the Earth is called its obliquity by scientists.