Prime lenses are lenses that have a single focal length rather than multiple as found in zoom lenses. Prime lenses are usually faster than zooms and are smaller and lighter than their counterparts. A professional prime will still be heavier than a kit zoom lens, but compared to zooms in their own class they are less cumbersome. Common maximum apertures found in prime lenses range from f/2.8 to f/1.2. While there are very expensive prime lenses available, their relative simplicity when compared to a zoom means that there are some very inexpensive options that are fast and sharp. A 50mm f/1.8 is an ideal beginner's lens as it's faster than a kit lens, dirt cheap, and will provide the coveted bokeh just about everyone wants when they get their first DSLR.