The difference between Solstice and Equinox are given below:

(i) The revolution of the Earth is responsible for bringing about changes in the season. Day and night are caused due to the rotation of the Earth.
(ii) The portion of the Earth facing the Sun would always experience day, thus bringing continuous warmth to ie region. The other half would remain in Darkness and would be freezing cold all the time. would not have been possible in such extreme conditions.

The circle that divides the day from the night on the globe is called the Circle of Illumination. In the following image, the shadowed portion of the Earth experiences day and the white portion of the Earth experiences night. The circle that divides the two is the Circle of Illumination.

The seasons are changed on the Earth because of the inclination of the Earth's axis in a fixed direction and due to the change in the position of the Earth around the sun.
On 21st June, the Northern hemisphere is tilted towards the sun. These areas receive more heat because the sun rays fall directly on the tropic of Cancer.
The tropic of Capricorn receives direct sun rays due to tilting of South Pole towards the sun on 22nd December.
The Northern hemisphere experiences autumn season while Southern hemisphere spring season on 23rd September. On 21st March, itIS spring in Northern hemisphere and autumn in Southern hemisphere.

The Earth rotates from West to East on its axis. The Earth takes about 24 hours to complete one rotation around its axis. The period of rotation is known as the earthday. The spherical shape of the Earth allows only one half of the Earth to receive sunlight at a time.
The portion facing the sun experiences day, while the other half away from the sun experiences night. It is because of the rotation of the Earth that allows day and night following each other regularly.

The difference between the summer solstice and the winter solstice is as follows:
Summer Solstice In the Northern hemisphere the longest day and the shortest night occur on 21st June. The Sunrays fall directly on the tropic of Cancer. All these conditions are opposite in Southern hemisphere and it is winter there. The nights are longer than the days in Southern hemisphere. This position of the Earth is called the summer solstice.
Winter Solstice The tropic of Capricorn receives direct rays due to tilting of South Pole towards the sun on 22nd December. The vertically falling sun rays at the tropic of Capricorn 23 1/2° provide heat to a larger portion of it. Therefore, it is summer in Southern hemisphere. This position of the Earth is called the winter solstice.

The shadows are long in the morning and evening and shorter at noon. It is the effect of the slanting and direct rays of the Sun. When the rays of the Sun are overhead in afternoon, shadows are the shortest. The rays of the Sun are slanting during evening and morning hence, the shadows are longer.

The change of seasons is caused due to the revolution of the Earth around the Sun.