These can be referred to as performance boards because they are the type one uses to rip and shred. You don't need one of these if you are just starting out. Learn to surf, then get a shortboard. Performance boards feature a narrow nose for pressing over the ledges of pitching waves and offer a narrow tail for carving deep bottom turns and cutbacks. These boards are called guns because they help the surfer to shoot down the face of the wave with maximum speed.
Guns also paddle more efficiently to help the surfer drop in and paddle through sets.
Performance boards can vary in length from less than 6 feet for smaller surf to 9 feet for the biggest surf. If your just starting and your strapped for the cash, I would look into getting a nice used board. Send it in Email or post it to the forum . When there is no more separation between 'this' and 'that,' it is called the still-point of the Tao. At the still point in the center of the circle one can see the infinite in all things.