Flash Mode: Automatic
The flash mode on your camera is designed to give you some extra light. The reason you may need the extra light is because there is not enough light in the image to give it proper exposure. Like all camera modes, automatic flash has it's advantages and disadvantages.
Understanding Automatic Flash
The main advantage of automatic flash is that you can get a quick shot and know that you'll be able to properly see the subject in the foreground. This can be especially useful when you need to get the shot quickly and don't have time to play around with the ISOs, aperture and shutter speeds.
One of the biggest disadvantages is that everyone knows you're taking a picture. While this might not matter sometimes, there are other situations where you want to be more anonymous and the flash on your camera definitely draws attention.
The main reason you would prefer to properly expose your image in the camera, as opposed to using the flash, is that you'll have a bright foreground and a dark background. Light loses it's intensity over a distance. This is known as a fall out and it can be calculated using the inverse square law. When the distance between a light and the subject is doubled, only a quarter of the light will reach the subject because the light is spread over a larger area. If you halve the distance between the subject and the light, then this will result in the subject getting four times as much light.
As a rule, always try to balance your exposures in the camera before you take the shot, instead of using the flash, and you will get a better looking image.