When the northern hemisphere of the earth is on a small angle towards the sun the light can reach it easier and the energy with the heat can to, this is summer
The earth is always spinning and orbiting the sun, so as the summer ends then comes autumn which is a season in between summer and winter. The angle of the sun is in between a small and large angle.
While summer is happening in the northern hemisphere, in the southern hemisphere it is winter. This is because the angle of the earth towards the sun is at a large angle which means its harder for the sun to reach the southern hemisphere at this point.
After winter comes spring which is between winter and summer. This is when the sun is between a large to small angle.
This cycle is always rotating. This means that when the northern hemisphere is having a winter, the southern hemisphere is having a summer. And when the northern hemisphere is having a spring, the southern hemisphere is having an autumn. With the angle on the earth depending on the season.
Northern Hemisphere: Winter Spring Summer AutumnSouthern Hemisphere: Summer Autumn Winter SpringThis is the cycle that happens as the earth moves around the sun.