Winter is the icicle time of Earth causing it to be colder and less
enjoyable. Like the feeling of getting a brain freeze or swallowing an ice cube whole. Summer is the warm time of Earth making it feel like you’re bathing in a hot tub.
Why do we have the seasons? Well, it because of the Earth's tilt. Since it is tilted on a 23.5 degree angle we have seasons. During winter the northern hemisphere is facing away from the sun, making it colder and having less light and contact from the sun's rays. The Earth does not flip over and over during the seasons, it just rotates around the sun. Summer is when the northern hemisphere is facing the sun and is getting more light and heat from the sun's rays.
The brisk cold and the sweltering hot, we experience this because of our tilt. A Mars sized object hit the Earth at the beginning of Earth’s formation causing the tilt, and creating the moon.