Research

Shutter Speed

Shutter speed is the length of time a camera's shutter is open when taking a photograph (shooting the video)
Here are some examples:

The smaller the number, the blurrier image is.

Aperture

Is a hole or an opening through which light travels.  

Here is a video which tells a lot about it.

Basically, the smaller the number of aperture, the bigger the hole and more light comes into your camera. If the number is big, there will be less light coming into your camera.

ISO

Iso measures the sensitivity of image sensor. The higher the number the more sensitive your camera is to light. Higher ISO settings are usually used in dark situations .