intisity
What is the strength of area falling on a certain area
The dark area formed by an object that blocks out light is called a shadow.
shadow
It's called the lunula (the whitish half-moon at the base of the nail).
A cooler area on the sun is called a sunspot
What is the strength of area falling on a certain area
The amount of sunlight light falling on a given area changes as the Earth rotates -- night & day
The purpose of a lamp is to light up a small area.
value
The dark area formed by an object that blocks out light is called a shadow.
it is called an mandorla
The lighter-colored regions of the moon are called Highlands
shadow
That whitish crescent shaped area at the base of a finger nail is called the lunula.
Its an opaque object.
I believe that is called 'shadow' or 'shade'.
Brightness