Image Stabilisation refers to a range of technologies designed to counter image blur. These can be divided into three categories: mechanical, sensitivity-based or electronic. Mechanical stabilisation concerns the movement of either elements within a lens or the sensor inside a camera, to offset any movement from the camera as the image is captured
Sensitivity-based system adjust the camera's sensitivity to a point where the resulting shutter speed - which increases with sensitivity - will be fast enough to capture the image sharply
Electronic systems are less frequently used in stills cameras than the other two varieties, although where these are used they typically work by combining separate exposures to process out the blurring.