Instead of having to decide between a normal and a telephoto lens, for instance, you could use a focal length anywhere between the two. The convenience and versatility of zoom lenses has made them popular with photographers. This 28 to 200 mm zoom lens could replace all the single-focal length lenses behind it. Equally enticing is that a zoom lens lets you fine-tune your compositions without having to change your shooting position. Instead of walking closer to or farther from your subject, you can remain in place and adjust the focal length to fit the composition you have in mind.
Zoom lenses are available in a variety of focal-length ranges.
They're also more expensive. Their close-focusing distances may be as far as 10 feet. They provide you with substantial telephoto capability, but still allow you to broaden the composition when necessary. Many zooms in this range also have macro capability, which lets you take close-ups of small objects. You focus the lens and change focal lengths by pushing or pulling on the focusing collar.