A blade is a tool or weapon with an edge that is designed to puncture, chop, slice or scrape surfaces or materials. A blade may be made from metal (usually steel), ceramic, or other material. Blades are one of humanity`s oldest tools, and continue to be used for combat, food preparation, and other purposes.
A combat knife is a fighting knife designed solely for military use and primarily intended for hand-to-hand or close combat fighting.
Since the end of trench warfare, most military combat knives have been secondarily designed for utility use (clearing foliage, chopping branches for cover, opening ammunition crates, etc.) in addition to their original role as close-quarter combat weapons, and may be referred to as "fighting-utility knives".
On the other hand, military knives that are intended primarily for use in a role other than combat are typically referred to by their primary role, such as "utility knife" or "survival knife".
A dagger is a knife with a very sharp point and two or more sharp edges, typically designed or capable of being used as a thrusting or stabbing weapon. Daggers have been used throughout human experience for close combat confrontations, and many cultures have used adorned daggers in ritual and ceremonial contexts. The distinctive shape and historic usage of the dagger have made it iconic and symbolic. A dagger in the modern sense is a weapon designed for close-proximity combat or self-defence; due to its use in historic weapon assemblages, it has associations with maleness and martiality. Double-edged knives, however, play different sorts of roles in different social contexts. In some cultures, they are neither a weapon nor a tool, but a potent symbol of manhood; in others they are ritual objects used in body modifications such as circumcision.
Lock-blade knives Knives with locking blades, often referred to as lock-blade knives or clasp knives, have a locking mechanism that locks the blade into its fully opened position. This lock must be released in a distinct action before the knife can be folded. The lock-blade knife improves safety by preventing accidental blade closure while cutting.