Focal length is a key specification of a camera lens that indicates both its magnification and angle of view. It determines how much of a scene is captured and how large subjects appear in the frame. For a 35mm camera, a lens with a focal length of around 43mm roughly approximates the perspective of the human eye.
Lenses shorter than this are classed as wide-angle, capturing a broader view, while longer focal lengths are considered telephoto, magnifying distant subjects. In digital photography, the small size of a compact camera's CCD sensor means standard focal lengths are typically between 6mm and 8mm, whereas medium-format cameras often use lenses around 80mm. Understanding focal length helps photographers choose the right lens for composition, perspective, and subject emphasis.