Folding is the designation to all, non-automatic, folding knives. From a basic swiss knife to a high end custom folding knife, any knife with a blade that folds into the handle can be designated a folding knife. Automatic knives (jack-knives, switchblades, autos) are not included in this category of knife, despite their folding design, because of their restriction by state and country laws across the globe. The same applies to the double designation of folding-locking knives, a current contraband in the United Kingdom.

Folding knives effectively double the length of tool one can carry with them as the blade is usually completely concealed in the handle. This also elinates the need for a sheath in most cases. However, as there is no tang and the handle is hollow during the use of the blade itself the knife will be a lot weaker and liable to snap at the pivot hinge under high stress operation. Furthermore, the fact it has a deep cavity, hinge and blade retention and stop pins, the cleaning of the knife, should it become dirty enough to warrant a scrub, is much more difficult. In many cases this leads to a general poor upkeep of the blade and many manufacturers offer their folding blades with coated blades to help stave off oxidisation of the steel.