A ‘zoom lens’ is a lens with adjustable focal length. Often the term is confused with a telephoto. Where a zoom lens may be a telephoto, it isn’t necessarily so.
In the case of my 18-135mm Fujinon lens, this is a wide-angle to medium telephoto range zoom.
I used this to good advantage the other day at Millers Falls, Massachusetts to make a sequence of photos of New England Central’s southward road freight 611.
Both of these photos were exposed from the same vantage point. All I did was adjust the focal length of the zoom as the train approached.