There is a lot of confusion nowadays over what exactly a tactical knife is or is not. Part of the reason for this is that many knife companies use the term "tactical knife" to describe blades that really don't fit the original definition. From a marketing stand point, there's little denying that the one little word "tactical" definitely makes the knife sound cool, and can work as a selling point. But this still leaves the original question of what exactly is the definition?
Originally, a tactical knife was one that was made for the military for use in combat or for use as a tool out in the field (or both). In fact, for a long time combat knife was synonymous with tactical knife. These blades were most often not folding knives, but think of the classic blades made by the Buck Knife Company as an example of what a really good tactical based blade would be like. These tools had to have a variety of functions, including helping soldiers in wilderness survival situations, acting as an effective combat or self defense weapon, and some were even designed with a small serration for sawing of small branches.
These were first made in World War II, and became standard issue for every soldier. Some of the most famous tactical knives come from the black blades of the Navy SEALs, but special forces are not the only military groups who still use specialty combat knives.
There are many modern knives that are marked as tactical, even when they're not. Most pocket knives are going to fall in this category, although there is a such thing as a folding tactical knife, so there are the occasional oddities. Many small throwing knives are also referred to as tactical knives since many special forces are trained to use these weapons effectively. Because the term "tactical" is not copyrighted, there are many different types of blades for sale that have this adjective on the box whether or not they have ever been tested or used in the military.
Still, finding a good tactical knife is not that difficult, as there are many different options for consumers to purchase. Depending on what your specific needs are, there is almost certainly a tactical knife that can serve as an appropriate option for you.