With optical image stabilization, part of the lens physically moves to counteract any camera movement when you take the picture; if your hands are shaking, an element inside the lens shakes too to counter the movement.

Does image stabilization affect image quality?

So really, image stabilization is the most important in situations where you don't have enough light to get a fast shutter speed. It tends to come in handy at sunset, sunrise, and indoors. In most cases, image stabilization will give you the same image quality at 3 to 4 shutter speed stops slower than usual.

What does optical image Stabilisation do?

OIS is a mechanical technique used in imaging devices to stabilize the recording image by controlling the optical path to the image sensor. The two main methods of OIS in compact camera modules are implemented by either moving the position of the lens (lens shift) or the module itself (module tilt).