PARTS OF THE BOARD AND WHAT THEY DO

Deck - The top of the board where you lay

Nose - The front, where you hold on

Rail - The side of the board

Tail - The back end

Channels - Gouged out areas on the bottom of the board that help to channel the water to enhance performance. There are MANY channel configurations out there, and basically, they help you hold on the face of the wave better and enhance speed, but can decrease maneuverability, ALTHOUGH when combined with certain tail designs and templates can work perfectly and be very maneuverable. Especially effective in this respect with bat tails. If the channels are angled toward the center of the tail, the theory is that it will make the board looser, easier to maneuver. If the channels are straighter off the tail, supposedly the board will be quicker, but less maneuverable. 

Mesh - A chicken wire-like plastic material sandwiched into the core of a board to enhance projection and durability.

Template - This just means the basic shape of the board (ie: narrow nose, wide nose, etc.)

Chine - This is the part of the board's rail that wraps over the side of the board from the deck. It's usually much smaller than the bottom part of the rail.

Stringer - Now offered by many manufacturers, stringers made a brief appearance in the 80's, and are enjoying a comeback. It's basically a straight rod inserted into the board to maintain the stiffness of the board. Can be made of many different materials. Lengthens the life of the core.

TAILS

Bat Tail - A tail shape that slightly resembles the wingspan of a bat. There are many varieties of bat tail, but basically, there are points at either end of the tail, with some form of rounded or pointed area in the center of the tail. Bat tails are generally loose, and provide lots of maneverability. Probably not the call for DKers or people that ride nothing but barrels.

Crescent Tail - First introduced by Morey in 1982, this is a tail that can either be clipped or full. The clipped version has square "pegs" on either side of the tail, and a "U" shape connecting the pegs. The full crescent is the same "U" shape, but it leads to a point on either side of the tail. The clipped version has very good holding characteristics and isn't likely to slide out, and still offers good maneuverability. If you don't like channels, this is a good tail design. The full crescent is the call for full-time DK riders. It provides maximum hold, but doesn't release easily if you like to spin.

Fork Tail - Just a variation on the bat tail. Incorporates the benefits of the bat with the bite of the crescent for dropknee riding. 

CORES, FOAM TYPES and BOTTOM SKIN TYPES

Crosslink - A type of foam characterized by it's denser, more compact feel, and unwillingness to absorb water. Very durable deck and rail foam material. Usually more expensive than standard polyethylene foam. It is known by other names that companies use to make it sound exciting (ie: DuraDeck, etc.).

Arcel - Developed for bodyboards in the mid-80's, this is a light, strong foam used for bodyboard cores. It's properties include maintaining it's stiffness even in warm waters. The downside is the ease with which it dents when you squeeze it.

Polypropylene - The newest wave of core material. Polypro is light, springy, and strong. It is fast replacing Arcel and Dow as the cores of choice. Like every core though, it's not uncreaseable and it is the most expensive of all cores. Many companies use their own names for it. In most cases, it's just polypro.
It comes in two types. Extruded polypro is made from strands of polypropylene and offers very good projection and durability in the board. Beaded polypro is a step up and is extremely lightweight, durable, water-resistant, and as a result, expensive, but you get what you pay for. 

Majikore - LMNOP's version of Polypro, with a sandwich layer on either side of the core to make it stiffer.

Dow or polyethylene - Used to make bodyboards for 20 years, it's still the standard foam. It's compact and comes in different densities, and has excellent projection and super performance, but isn't as long-lasting as polypro unless combined with some kind of internal stiffener like mesh or a stringer. It's used on the deck and rails of most bodyboards as well.

Surlyn - Invented by chemical giant Dupont, it's the stuff golf balls are covered in, and many bodyboards have on the bottom. It's slick and durable, has great speed and projection.

HDPE - High Density Polyethylene looks and feels very similar to Surlyn, but it's a softer, less durable bottom material that performs very well, but keeps the cost of the board down. Works great when combined with stiffer cores, or cores with stringers.