A telephoto zoom lens is a type of camera lens that allows photographers to capture distant subjects with clarity. It has a variable focal length, meaning you can zoom in and out to frame your shot without moving closer. This feature is particularly useful for wildlife photography, sports events, and portraiture, where getting close to the subject may not be possible. These lenses typically have a longer physical length and can produce a shallow depth of field, which helps to blur the background and emphasize the subject. Popular brands like Canon, Nikon, and Sony offer a range of telephoto zoom lenses to suit different photography needs.