Seasons
Seasons - Experiment
To understand how the Axial Tilt can make it hotter or colder, try the following experiment.
Seasons Animation
Earth's Tilt

Credit: NSO
In the picture on the right, you can see that the Earth "tilts" towards the Sun by around 23°. This is called the Axial Tilt of the Earth. The "poles" sticking out of top and bottom of the Earth are not real of course; they are just there to show you the axis points around which the Earth spins - known as the North and South Poles.
Seasons

Credit: www.pngall.com
The four seasons, Spring, Summer, Autumn and Winter each happen once a year.