Whatever answer I give you will be wrong in 12 hours.
The Earth spins on its axis every 24 hours, so each side of the planet gets about 12 hours of day light per day. (Less in winter, and more in summer, due to the 23 degreetilt of the axis.)
If you mean "which side of planet Earth", that changes all the time, as Earth rotates.
The half of the Earth facing the sun is considered the light side, while the half facing away is in darkness. This creates day and night as the Earth rotates on its axis.
If the earth does not rotate, we will not have night and day. One side of the world will always be dark, and one side will always be light.
The earth is move around everyday and the other side of the earth is facing away from the light so we have night if we have light from the sun we have day. Day happen everyday and so does night.
Because the earth is a ball, and the sun is the only light source responsible for day and night, the earth can only be illuminated on one side at a time. Luckily, the earth spins so that every side of the earth gets a piece of sunshine. The rotation of the earth is what causes day and night.
Earth is continuously rotating on its axis around the sun and it is a sphere. The part of Earth that comes in front of sun gets light from sun and hence day Appers on these areas while the areas which are on the other side get night.
The formation of day and night suggests the rectilinear propagation of light because when the Earth rotates on its axis, the sunlight falls on one side of the Earth creating day, while the other side facing away from the Sun is in darkness, creating night. This implies that light travels in straight lines from the Sun to the Earth, illuminating only the side facing the Sun at any given time.
Day and night are caused by the rotation of the Earth on its axis. When one side of the Earth faces the Sun, it is daytime, and the other side experiences nighttime. This creates a cycle of light and darkness as the Earth rotates.
During the day the side of the Earth you are on faces our local star (the Sun) which generates energy in its core by a process of nuclear fusion. This energy escape out of the surface of the sun in the form of light and this light illuminates the sun-ward facing parts of the Earth. This makes it light during the day. At night the part of the Earth you are on is not facing the Sun and therefore you are in the shadow of the Earth and it is dark.
The main thing to remember is that the Earth is a sphere. It's the same sort of shape as a basketball. The Earth blocks out the Sun so it can't light the side of Earth facing away from the Sun. A simple experiment: Take a ball and hold it to a light. The half of the ball facing the light will be lit up and the other side will be dark. Rotate the ball and different parts will now be light and dark. That's like what happens as the Earth rotates. That's why a place on Earth has day then night.
The line that separates the dark half from the light half of the Earth is called the terminator. This line represents the boundary between day and night, where the sun's light is directly illuminating one side of the planet while the other side remains in shadow. The position of the terminator changes throughout the day as the Earth rotates on its axis.
Day and night are caused by the rotation of the Earth on its axis. During the day, the side of the Earth facing the Sun experiences daylight, while the opposite side experiences night. As the Earth rotates, different parts of the planet are exposed to the Sun's light, creating the cycle of day and night.