"Zoom" and "telephoto" lenses are generally two terms that aren't directly related.
A zoom lens is one which can change its focal length -- that is, its apparent magnification. For example, your 18-55 "zooms" from 18mm (which is a moderately wide angle) up to 55mm (which is moderately "zoomed in" or "close" or -- special name -- "telephoto").
A telephoto lens is one with a large focal length. Looking through the lens will make things appear very close. Often telephoto lenses are zooms, but there's no guarantee -- you could find a 200mm telephoto which doesn't zoom, it just stays at 200mm. That will put you very close to your subject, however!
So, a zoom lens may be telephoto, and vice versa. However, neither one implies the other. For example, I have a 10-24mm lens, which is an "ultrawide zoom". It zooms from 10mm (very very wide angle) to 24mm (moderately wide angle). There's nothing telephoto about it, but it still zooms.
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