Optical zoom refers to the ability of a camera lens to magnify an image using the physical movement of its glass elements. Unlike digital zoom, which enlarges a portion of the image and can reduce quality, optical zoom maintains clarity and detail by adjusting the focal length. This feature is commonly found in cameras, including those in smartphones and professional photography equipment. The measurement of optical zoom is expressed as a ratio, such as 3x or 10x, indicating how much closer the subject appears compared to the lens's widest angle. For example, a 10x optical zoom allows a photographer to capture distant subjects without losing image quality, making it ideal for wildlife photography or sports events.