Photography is the process of recording visual images by capturing light rays on a light-sensitive recording medium (e.g. film or digital CCD). It can be thought of as two pursuits: Technical: The science of setting up the camera and the recording medium to take images in a controlled way.
Aperture: The aperture setting controls how much light and how wide the lens is open before the photo is taken. For example if the lens is closed smaller at an aperture of f16, the image will be clear and crisp everywhere. Where as if the lens is open less, at about f1.2, the camera will blur out the background and there will be one main focus point.
Exposure: If the exposure setting is set incorrectly and does not suit the surrounding environment where the photograph Is being taken, it could mean that your photo could turn out to bright or too dark. If you are in a brighter environment, outside I sunlight for example, the exposure would be around 0 or -1. It would be the same for a darker room however you would turn it up to 1 or 2 to make sure the lens opens more to let in more light from the surroundings.
Sutter speed: If you need to capture movement within a photo , you are able to change the shutter speed to a slower setting to make sure you can capture the movement. The longer the shutter speed, for example 20 seconds, the more movement you are able to capture.
White balance: By adjusting the white balance of your image, you can create a warmer or cooler toned image. By setting the camera to a white balance of 2500k, for example, the image appears a lot cooler and more blue toned. However, if the white balance was set higher the image would have more warm tones which could be used to make an image look old
Depth of field: A small depth of field can be used to make the focal subject stand out with the rest of the image by using a higher aperture, meaning the background is blurred out whilst the main subject is the only thing in focus. If you use a much smaller aperture, the background will be more in focus meaning it has a bigger depth of field.