A telephoto lens is a type of camera lens designed to capture distant subjects with clarity. It has a long focal length, which allows photographers to zoom in on faraway objects without losing detail. This makes telephoto lenses popular for wildlife photography, sports events, and portraiture, where getting close to the subject may not be possible. Telephoto lenses can also create a shallow depth of field, which helps to blur the background and emphasize the subject. This effect is often used in portrait photography to make the subject stand out. Overall, telephoto lenses are essential tools for capturing images from a distance.