A zoom lens is a type of camera lens that allows the photographer to change the focal length, enabling them to zoom in or out on a subject without needing to change the lens. This versatility makes zoom lenses popular for various photography styles, from landscapes to portraits, as they can capture a wide range of scenes. Zoom lenses typically have a variable focal length, such as 18-55mm or 70-200mm, which indicates the range of distances they can focus on. They are designed with multiple glass elements to maintain image quality while adjusting the zoom. Many photographers appreciate the convenience of having multiple focal lengths in one lens, making it easier to adapt to different shooting situations.