For me, as for many photographers, light is the most important element in any photograph. Take these two photos for example. They were taken minutes appart during the June wildflower bloom in Howard Prairie in the southern Oregon Cascades. I like both, and other than the light, both are very similar. However, in the first image the sun has not yet crested the ridgeline so the scene is lit by indirect light that is being reflected from the sky and off of the surrounding landscape. It creates a very even wash of light with subtle transitions from darker to lighter areas and the feel that light is glowing from all directions, which it basically is. In the second image the sun has just crested the ridge and direct light is shining on the meadow and strongly backlighting the flowers and grass. The color is warmer, the contrast in the scene is much greater and there is a much stronger sense of the direction of the light. Knowing the characterisitics of different types of outdoor lighting situations helps me be to plan the timing of a photo to best convey the scene the way I envision it.