essential information.

photography.
'photo' is another word for light and 'graph', taken from the word photography refers to drawing/tracing/sketching. basically, photography is drawing with light. my camera is the brush, light is my palette full of colors and the world is my wide canvas.
so how exactly do we paint with light using our cameras? click here for further explanation.
to understand how the camera works, we must first understand the properties of light. for example, light travels in a straight path. light can also be diffused or refracted.
how does the human eye see? we are able to see an object in daylight because light from the sun falls upon it and it is is diffused and scattered in all directions. this is known as diffuse light. we 'see' the object because some of the scattered diffuse lights goes directly into our eyes as a beam or rays of light. of course, more than one ray will enter our eyes, thus constructing the image that we see. more explanations here.

why bother with the explaining? why did they send a man to the moon? same question, same answer.

references: Aussie Photographer Neil Creek & howstuffworks.