The effect of the Earth facing the sun is so that you can have daytime. Another effect is so that our planet can substain life.
The Earth's position in orbit determines whether it is facing toward or away from the Sun. During daytime in a particular region, that part of the Earth is facing the Sun, while during nighttime, it is facing away.
Light
When its "summer time " the earth is facing toward the sun , and when it is winter the earth is facing away from the sun .
The Earth tilts toward the sun for spring and summer. So the earth is not facing away from the Sun. If we were not facing the sun, we'd be cold because it would be fall going into winter.
Away
As the earth spins one side is facing toward the sun and the other side is facing away from the sun which is night time
Away
The sun is always 'facing' the earth. If the northern hemisphere is tilted toward the sun, the season is summer, in the northern hemisphere and winter in the southern hemisphere.
The Earth tilts toward the sun at an angle of 23.44 degrees, because the Earth rotates, the entire Earth tilts toward the sun during summer and away from the sun during winter.
The side that is facing the sun is in the daylight. It keeps changing. At any given moment, it would be the half directed toward the sun.
what is the period when a given part of earth is facing the sun
It is night in the hemisphere facing away from the Sun.