Definitions for "Prime Lens"
Keywords:  focal, zoom, lens, lenses, fewer
A fixed lens, 80mm, 105mm or 200mm are examples of of prime lenses. Prime lenses are often considered faster than zoom lenses because there are fewer elements inside thus a wider aperture is possible. Prime lenses often produce a higher quality image than a zoom as well, however you must change your lens every time you want a different focal length. Plus you have to carry around all those different lenses.
a fixed lens--the perspective does not change
a lens for a Single Lens Reflex (SLR) camera with a fixed focal length