Photographic lenses are optical devices used in cameras to focus light and capture images. They come in various types, such as wide-angle, telephoto, and macro, each designed for specific photography needs. The lens's focal length determines how much of a scene can be captured and how close or far away subjects appear. Lenses are made up of multiple glass elements that work together to reduce distortions and improve image quality. The aperture, an adjustable opening within the lens, controls the amount of light entering the camera, affecting exposure and depth of field. Understanding these components helps photographers achieve their desired results.