Section, Sectioning, or Sectioned may refer to:

Arts, entertainment and media

Section (music) In music, a section is a complete, but not independent, musical idea. Types of sections include the Introduction (music), introduction or intro, Exposition (music), exposition, Musical development, development, recapitulation (music), recapitul ...

, a complete, but not independent, musical idea * Section (typography), a subdivision, especially of a chapter, in books and documents **

Section sign The section sign (§) is a typographical character for referencing individually numbered sections of a document; it is frequently used when citing sections of a legal code. It is also known as the section symbol, section mark, double-s, or si ...

(§), typographical characters * Section (bookbinding), a group of sheets, folded in the middle, bound into the binding together * The Section (band), a 1970s American instrumental rock band * ''The Outpost'' (1995 film), also known as ''The Section'' * Section, an instrumental group within an

orchestra An orchestra (; ) is a large instrumental ensemble typical of classical music, which combines instruments from different families. There are typically four main sections of instruments: * String instruments, such as the violin, viola, cello, ...

* "Section", a song by 2 Chainz from the 2016 album '' ColleGrove'' * "Sectioning" (''Peep Show''), a 2005 television episode * David "Section" Mason, a fictional character in '' Call of Duty: Black Ops II''

Organisations

* Section (Alpine club) *

Section (military unit) A section is a military sub-subunit. It usually consists of between 6 and 20 personnel. NATO and U.S. doctrine define a section as an organization "larger than a squad, but smaller than a platoon." As such, two or more sections usually make up ...

* Section (Scouting)

Science, technology and mathematics

Science

* Section (archaeology), a view in part of the archaeological sequence showing it in the vertical plane * Section (biology), a taxonomic rank that is applied differently between botany and zoology **

Section (botany) In botany, a section () is a taxonomic rank below the genus, but above the species. The subgenus, if present, is higher than the section; and the rank of Series (botany), series, if present, is below the section. Sections may in turn be divided i ...

* Histological section, a thin slice of tissue used for microscopic examination, achieved by sectioning

Mathematics

Section (category theory) In category theory, a branch of mathematics, a section is a right inverse of some morphism. Dually, a retraction is a left inverse of some morphism. In other words, if f: X\to Y and g: Y\to X are morphisms whose composition f \circ g: Y\to Y ...

, a right inverse of some morphism **

Section (fiber bundle) In the mathematical field of topology, a section (or cross section) of a fiber bundle E is a continuous right inverse of the projection function \pi. In other words, if E is a fiber bundle over a base space, B: : \pi \colon E \to B then ...

, in topology ** Part of a

sheaf (mathematics) In mathematics, a sheaf (: sheaves) is a tool for systematically tracking data (such as sets, abelian groups, rings) attached to the open sets of a topological space and defined locally with regard to them. For example, for each open set, the ...

* Section (group theory), a quotient object of a subobject *

Conic section A conic section, conic or a quadratic curve is a curve obtained from a cone's surface intersecting a plane. The three types of conic section are the hyperbola, the parabola, and the ellipse; the circle is a special case of the ellipse, tho ...

, intersection of a cone and a plane

Other uses in science and technology

* , an

HTML5 HTML5 (Hypertext Markup Language 5) is a markup language used for structuring and presenting hypertext documents on the World Wide Web. It was the fifth and final major HTML version that is now a retired World Wide Web Consortium (W3C) recommend ...

markup * Sectioning (car), a customization of hot rod cars

Surveying

* Section (United States land surveying), an area nominally one square mile * Section, an area of one square mile in

Dominion Land Survey The Dominion Land Survey (DLS; ) is the method used to divide most of Western Canada into one-square-mile (2.6 km2) sections for agricultural and other purposes. It is based on the layout of the Public Land Survey System used in the United St ...

, Western Canada * Section, part of the Alberta Township System

Other uses

* Section, Alabama, a town in the United States *

Section (rail transport) In rail transport, a section could refer to: a portion of a train that may be operated independently and/or combined with other sections to operate as a single unit; or a portion of railway line designated for railway signalling, signalling or main ...

, a portion of railway line or a portion of a train *

Sectioning Involuntary commitment, civil commitment, or involuntary hospitalization/hospitalisation, or informally in Britain sectioning, being sectioned, commitment, or being committed, is a legal process through which an individual who is deemed by a qual ...

, involuntary commitment for severe mental illness