A utility knife is a knife used for general or utility purposes. The utility knife was originally a fixed blade knife with a cutting edge suitable for general work such as cutting hides and cordage, scraping hides, butchering animals, cleaning fish, and other tasks. Craft knives are tools mostly used for crafts. Today, the term "utility knife" also includes small folding or retractable-blade knives suited for use in the modern workplace or in the construction industry.
There is also a utility knife for kitchen use which is between a chef's knife and paring knife in size.
The fixed-blade utility knife was developed some 500,000 years ago, when human ancestors began to make knives made of stone. These knives were general-purpose tools, designed for cutting and shaping wooden implements, scraping hides, preparing food, and for other utilitarian purposes.
By the 19th century the fixed-blade utility knife had evolved into a steel-bladed outdoors field knife capable of butchering game, cutting wood, and preparing campfires and meals. With the invention of the backspring, pocket-size utility knives were introduced with folding blades and other folding tools designed to increase the utility of the overall design. The folding pocketknife and utility tool is typified by the Camper or Boy Scout pocketknife, the U.S. folding utility knife, the Swiss Army Knife, and by multi-tools fitted with knife blades. The development of stronger locking blade mechanisms for folding knives—as with the Spanish navaja, the Opinel, and the Buck 110 Folding Hunter—significantly increased the utility of such knives when employed for heavy-duty tasks such as preparing game or cutting through dense or tough materials.
The fixed or folding blade utility knife is popular for both indoor and outdoor use. One of the most popular types of workplace utility knife is the retractable or folding utility knife (also known as a Stanley knife, box cutter, X-Acto knife, or by various other names). These types of utility knives are designed as multi-purpose cutting tools for use in a variety of trades and crafts. Designed to be lightweight and easy to carry and use, utility knives are commonly used in factories, warehouses, construction projects, and other situations where a tool is routinely needed to mark cut lines, trim plastic or wood materials, or to cut tape, cord, strapping, cardboard, or other packaging material.