Basicly these are the three parameters that affect how your picture looks. Each of these change the exposure of the Picture in a very different way:
Aperture. The aperture is the hole on your lens through which light travels before it hits the sensor. If you open up the aperture, more light enters the camera, and the image appears brighter. If you close the aperture, less light enters the camera, and the image appears darker.
Shutter Speed. When you adjust your shutter speed, you’re changing the duration of time the shutter stays open to allow light into the camera. If the shutter is open longer, more light will enter the camera and hit the sensor. But if you increase the shutter speed, the shutter opens for a shorter period of time and less light hits the sensor overall. This will result in a darker image.
ISO Speed. This is a number that determines the image sensor’s sensitivity to light. If it’s more sensitive, you’ll end up with a brighter image. If it’s less sensitive, you’ll end up with a darker image. ISO speed also impacts the graininess of an image. If you pick a really high ISO speed, the resulting image will be much more grainy than if you were to use a low ISO speed.
Ihope Icould help you to understand your camera better.