How does lighting affect photography?: The direction that the light is coming in, in your picture will affect the rest of the photo. The lighting in a picture could change the entire product. If the lighting is good but the photo is not the greatest you will have a better result, since the lighting is good. If the lighting is bad but the photo is good, the overall product won't be the best it could be.
There are three different types of lighting in photography. Side lighting, front lighting and back lighting. Each one serves an important purpose and make each photo have an overall better product.
Lighting Pictures

This photo is displaying back lighting. It is back lighting because the subject is in the foreground and the light is coming through the picture in the background.

This photo is side lighting because the light is coming through the right side. The side the light comes in (left or right) does not matter, as long as it is coming on a side.

This photo is front lighting. The light is coming in the picture from in front of the subjects. In this case the lighting is the sun. Since the subjects are facing the light that means the photographer (me) had there back facing the light, allowing the subjects to have the light coming through the photo. I chose this photo to be my featured image because I like how the light is coming through, and I think the subjects (my niece and nephew) are adorable. My niece was laughing and my nephew just discovered what a walkie-talkie is and was enjoying playing with that. We were outside that afternoon playing in the woods.

This photo above is showing front lighting. The light is coming from in front of my dog.

This photo above is an example of back lighting. The lighting is behind the subject.

The photo above is showing side lighting. The lighting in this photo is coming from the side of the subject.
Shadow Pictures

This photo above is an example of a hard shadow. the shadows of the chairs are very defined and easily noticeable.

This photo above is an example of soft shadows. The shadows from the chairs are not very strong. If you look quickly you could easily miss them, they kind of blend in with the floor.