There are two main parameters that influence a photo dramatically:

Exposure: Exposure is the amount of light that the camera's sensor is exposed to as a combination of shutter speed and aperture. The higher the exposure the more lit the photo is. Overexposed photos have large areas that are white as light saturates the sensor. The lower the exposure the darker the photo is. If the exposure is too low the photo is too dark or even completely black.

White balance: Different light sources have different color temperatures. Color temperature is measured in Kelvin (the details are beyond the scope of this article) and can also be described as color. For example consider the following light sources: daylight 5000K (5000 Kelvin) is white color, candle light 1800K is reddish light and regular bulb light 2500K is orange color. The white balance setting allows the camera to correct the photo color based on the light source. The setting can be either manual or automatic. Setting the white balance manually to a "wrong" light source can also be used for special effects such as reddish photos or orange photos. The exact details of white balance settings are beyond the scope of this article.

When you take a photo you set the camera to the right composition, zoom value, focus, flash, shutter speed, aperture value and white balance. Some of these values can be set automatically by the camera for you.

Many times it is better to take the same photo in different settings and later on choose which photo looks the best. This can be done manually by changing the settings and shooting again and again or automatically by using the auto bracketing feature. With auto bracketing the camera shoots a series of photos in different exposures and white balance settings. This can also be useful if you have to take a fast photo and do not have time to figure out the perfect settings. With one push of a button you can take a few photos with different settings and later on choose which one is the best.

Auto bracketing can be applied to the exposure or the white balance setting. In both cases it works the same - when you shoot a photo the camera shoots a series of photos for you (usually 3 or 5) each one with a setting that is a step lower or higher than the first photo. The size of that step can be chosen when putting the camera into auto bracketing mode.

For example when setting the camera to an exposure auto bracketing with 5 photos and step size of 1EV (one exposure unit) the camera will shoot 5 photos, one with the exposure you set (or that the camera automatically chose as the optimal one) one with exposure that is +1EV, one with -1EV, one with +2EV and one with -2EV.

The downside of using auto bracketing is memory consumption as each time you shoot a photo you actually shoot 3 or 5 photos resulting in the memory card being filled 3 or 5 times faster. If your memory card is large enough this should not be a problem.

If you have not done so already check how the auto bracketing feature works in your digital camera. Experiment with it and learn how to use it. Using auto bracketing to shoot hard photos like sunset photos and difficult lighting situation is very powerful. It is also very powerful when you do not have too much time to choose the right settings.