The final element in our photography triangle is shutter speed. This is defined by the amount of time that the shutter remains open and exposed to light.
The longer the shutter is open, the more light that hits the sensor and the shorter the shutter is open; the less light hits the sensor.
The shutter speed is either listed as a fraction of a second (1/60) or in whole seconds (1′, 2′). Some camera even allows for whole minutes, or an infinite amount of time (bulb). Shutter speed is a bit easier to understand than aperture, where the fraction 1/60 is one sixtieth of a second that the shutter is open.
Depending on what you are capturing, depends on the shutter speed that you will need. If you are capturing sport or wildlife, you may want to try and get a sharp image, freezing the action as it happens.
Capturing a slight blur, as seen in this image above can also be quite useful at demonstrating moments, such as the street below Somerset House in London or the image on the Southbank at London below
Short shutter speed = 1/2000 = freeze the action
Long shutter speed = 1′ = capture movement
Adjust your shutter for the light and remember the balance between ISO and aperture