Normale

Normale is a term with several related meanings used in different languages and disciplines. In Romance languages such as Italian and French, normale or normal is the adjective meaning ordinary, standard, or typical. In Italian, normale is used across contexts to denote something as usual or not exceptional, for example una situazione normale (an ordinary situation). In French, normale functions as the feminine form of normal.

In mathematics and geometry, normale is a technical noun and adjective referring to what is perpendicular. In Italian, la normale denotes the line or vector that is perpendicular to a curve or surface at a given point, and the term si riferisce to the normal line or normal vector. In French, la normale similarly designates the line perpendicular to a curve or surface at a point, as well as the normal vector in vector calculus. The concept is central to calculations of angles, projections, and surface interactions.

In physics and engineering, normale commonly appears in expressions describing perpendicular relationships. For instance, the forza normale (normal force) is the contact force exerted perpendicular to a surface. The term can also describe a normal component of a vector, as in components normal and tangential to a surface.

In statistics, the related expression distribuzione normale is standard for the normal distribution, widely known as the Gaussian distribution in many languages. While the English term “normale” is not used for the distribution, many Romance-language texts use normale in their translation of “normal.”

See also: normal vector, normal force, normal distribution.