The difference is the white balance. You probably have seen me with a crazy necklace on that has one stripe of black, one of gray and one of white. That is my white balance target. As fancy and advanced as digital cameras are, they cannot tell the difference between the three unless you tell it what they look like with your custom white balance setting.
Our human eye doesn't pay much attention to the subtle differences in the color value of light. But your digital camera sees it very clearly. When you step into open shade, white may take on a bluish color. If you are standing in the woods, it might be green as light reflects off of the leaves and bushes around you.
If you don't tell the camera what black and white look like in the setting that you are shooting in, then it has to guess. Your camera will assume that the darkest color it sees is black and the lightest color is white.
Even in the camera room it's important to use a custom white balance. Lots of things can make a difference in the color values you see, the backdrop, wall color, what the client is wearing.
Those of you who know Princess know that she is not a red head, but the image on the left makes it appear so. The camera is making assumptions on what the color value is. The middle shot includes the white balance target and that let's me tell the camera what color value it should be. The image on the right has the correct color balance.
If you are a photographer and you are interested in purchasing a white balance target, check out the link on the right for the one I use and recommend.