The word photography literally means to draw with light. It used to be light sensitive plates, film, and now light sensitive chips in digital cameras. Being able to control the light coming into your camera is the biggest element in photography. Once you can control the light you can take some amazing shots. There are three ways that a camera can control the light; the shutter speed, aperture size, and ISO Speed.
Shutter speed is the way you control the light coming into the camera by how long the camera holds open the cover to expose the chip. The bigger the number in shutter speed, the faster the shutter opens and closes. This means that the less light that comes in. So then what are the pros and cons to having different shutter speeds. When you have a slower shutter speed the easier it is for it to get blurry. This is why your picture gets blurry when you take a picture at night. However, blur can be controlled as well to your advantage. If you need a faster shutter speed, you then must compensate it with another setter.
The aperture size is how large the camera hole. The number that it gives is a ratio number, so the larger the number the smaller the hole is. The larger the hole, the more light that comes in. Which should you use? One aspect that is effected by aperture size is how big your depth of field is, or how much can be in focus at once. When you have a large aperture the smaller the depth of field. This is you can take a photo of something, and the rest of the background is not in focus. If you have a small aperture, then more of your image will be in focus.
The ISO speed is how sensitive your chip is. The higher the number the more sensitive the chip is. The more sensitive the chip is, the more light it can absorb. However, the higher you have your ISO speed the more gain there is going to be in your image.
These are the basics for controlling the light. When you get these down, you will change your ability to take amazing photos. Hope you have fun! Let me know if you have any comments or questions!