Exposure Triangle

The Exposure Triangle is composed of:

Shutter Speed.
ISO.
Aperture.



Shutter Speed: 
Shutter speed or Exposure time is the length of time when the film or digital sensor inside the camera is exposed to light, also when a camera's shutter is open when taking a photograph.

Examples:

ISO: 

ISO – Formerly ASA American Standards Association

In very basic terms, ISO is the level of sensitivity of your camera to available light. The lower the ISO number, the less sensitive it is to the light, while a higher ISO number increases the sensitivity of your camera. The component within your camera that can change sensitivity is called “image sensor” or simply “sensor”.

Example: