The exposure triangle is a common way of associating the three variables that determine the exposure of a photograph: aperture, shutter speed, and ISO. One must balance all three of these to achieve a desired result, an adjustment of one requiring adjustments of at least one of the others
Aperture – How much light passes through the lens and depth of field as shown below
Shutter speed – How long the the sensor is hit with light and affects the movement
The ISO– How much the processor amplifies the light collected by the sensor and the noise