So you're looking at buying a new knife, but you can't make heads or tails of all these terms they use to describe the blade. Well don't feel too bad my friend. Even the biggest, baddest knife maker out there had troubles making sense of all these terms when they first started, and once you get the ideas behind the terms down it really isn't as bad as it seems.
Let's start with a drop point blade. One of the two most common blade styles in current use, a drop point blade tends to have a gently curved spine (the back of the blade) that leads to a tip slightly lower than the back of the hilt or handle and a reasonably large "belly" (a curved cutting edge). This tends to result in a knife with good slicing characteristics and a strong tip that is less likely to break than many others. Many hunting knives and most chef's knives have this style of blade. The downside to this style is that it won't pierce things as easily or as well as some other styles.
A style that just as common as the drop point is the clip point, where the front portion of the blades spine appears to have been clipped off. Most Bowie knives use this style of blade as well as most butchers knives. The big advantage here is a tip that is second to none in piercing power coupled with a large belly giving you great slicing ability. The drawback is that the lack of metal in the spine near the tip causes a loss of strength which may lead to you breaking the tip off, especially if you try twisting or prying with the tip.
Another common blade type is the Trailing Point. This style typically has a curving spine that places the tip of the blade above the level of the grip and often a very thin blade. This maximizes the amount of belly available for use resulting in a fantastic slicing knife, which is why many skinning knives and all fillet knives use this style of blade. The downside is that the tip tends to be very weak to the point of being almost useless.
The next blade style is the dagger, also commonly called a spear point or needle point depending on the taper used. These are often, but not always sharpened on both edges, and are primarily designed to stab or make very fine adjustments to what every you're cutting. Many famous fighting knives, such as the V-42 used by the infamous Devil's Brigade of WWII, and most throwing knives use this style of blade. Interestingly enough, the original pen knife used a single edged blade of this style. It got it's name because it was designed to sharpen quill pens, and the name has continued to be used to this day, though it often refers to any traditional style folding pocket knife. Of course the main drawback to this style of blade is that it's for all practical purposes tip only, unless the blades got such a short taper at the very end that it looks more like a drop tip.
The next blade style is the Straight Back, though I don't often see this style used very often anymore. As it's name implies, this blade type feature a straight back or spine placing the tip in line with the top of the hilt. This style of blade makes for a very good chopper since the straight spine can be easily made as thick as one might wish, yet still has enough of a belly that you can make the type of slices needed to remove a hide or trim the excess fat from a hunk of meat. You see this style of blade on some of the old chef's and butcher knives such as Old Hickory or Chicago Cutlery.
The next style that comes to mind is the Sheepsfoot. This one is different from the others is that it features a ruler straight edge and it's the back or spine that curves down to meet the tip. The spine on this style of knife was made to be gripped by the supporting hand when needed, giving the potential for greater control for fine slicing, trimming, and whittling. The name comes from one of this styles earliest uses, trimming the hooves of sheep and horses; but it is best seen today in the kitchen in the form of the very popular santoku chef's knives. The drawback here is the lack of a usable tip.
The next style of blade, and one that has continued to grow in popularity is the tanto. With it's origins in ancient Japan, this knife features a chisel like tip, often with a heavy spine. Give it a heavy enough spine, and you've got a knife that will punch through a car door or almost anything else you might want to pierce without breaking. However since most of them have a straight cutting edge from hilt to start of their tip, while they might chop with the best of them, their slicing ability can be rather limited.
Then there's the spay point. The spay point is similar to the clip point, except that the curve of the blade and the clip are both so far out near the tip that penetrating anything is difficult at best. Originally developed for spay and neutering farm animals, these knives are a great choice for skinning animals where keeping the hide intact is a real concern.
The final style of knife is called the ulu and is based on an Inuit design. This blade is a quarter to two thirds of a circle with the handle in the middle. This produces a blade with no tip whatsoever and a huge belly which makes this style fantastic for scrapping things or cutting long thin strips from something. Perfect for leather working, thin veneers, and believe it or not, making hand rolled cigars. On the other hand, this blade type is as close to a one trick pony as you can get in the knife world, so you might easily go your entire life without ever seeing one outside of pictures.
So there you go, a quickly knife blade styles 101. Are there other styles? Well, maybe. I know some will say I should be more precise, and separate spear point blades and needle point blades into two separate categories, or maybe differentiate a Wharncliffe from a Sheepsfoot; but I personally think that's carrying precision to extremes. After all, the strengths and weaknesses of a Wharncliffe blade is so similar to the strengths and weaknesses of a Sheepsfoot blade that I really don't see any point in trying to separate them out. And with what you now know, coupled with the little bit of practical metallurgy I hope you got from last weeks ramble; picking out that new knife should be at least a bit easier.
In the meantime my friend, I must run. So take care of your self and I hope to see you in this little corner of cyberspace I call my own soon. And always remember, if it's worth doing, it's worth doing with attitude.