What is "section"

Section \Sec"tion\, n. [L. sectio, fr. secare, sectum, to cut; akin to E. saw a cutting instrument: cf. F. section. See Saw, and cf. Scion, Dissect, Insect, Secant, Segment.]

1. The act of cutting, or separation by cutting; as, the section of bodies.

2. A part separated from something; a division; a portion; a slice. Specifically:

   1. A distinct part or portion of a book or writing; a subdivision of a chapter; the division of a law or other writing; a paragraph; an article; hence, the character [sect], often used to denote such a division.

      It is hardly possible to give a distinct view of his several arguments in distinct sections.
      --Locke.

   2. A distinct part of a country or people, community, class, or the like; a part of a territory separated by geographical lines, or of a people considered as distinct.

      The extreme section of one class consists of bigoted dotards, the extreme section of the other consists of shallow and reckless empirics.
      --Macaulay.

   3. One of the portions, of one square mile each, into which the public lands of the United States are divided; one thirty-sixth part of a township. These sections are subdivided into quarter sections for sale under the homestead and pre["e]mption laws.

3. (Geom.) The figure made up of all the points common to a superficies and a solid which meet, or to two superficies which meet, or to two lines which meet. In the first case the section is a superficies, in the second a line, and in the third a point.

4. (Nat. Hist.) A division of a genus; a group of species separated by some distinction from others of the same genus; -- often indicated by the sign [sect].

5. (Mus.) A part of a musical period, composed of one or more phrases. See Phrase.

6. The description or representation of anything as it would appear if cut through by any intersecting plane; depiction of what is beyond a plane passing through, or supposed to pass through, an object, as a building, a machine, a succession of strata; profile. Note: In mechanical drawing, as in these Illustrations of a cannon, a longitudinal section

   1. usually represents the object as cut through its center lengthwise and vertically; a cross or transverse section

   2. , as cut crosswise and vertically; and a horizontal section

   3. , as cut through its center horizontally. Oblique sections are made at various angles. In architecture, a vertical section is a drawing showing the interior, the thickness of the walls, etc., as if made on a vertical plane passed through a building.

      Angular sections (Math.), a branch of analysis which treats of the relations of sines, tangents, etc., of arcs to the sines, tangents, etc., of their multiples or of their parts. [R.]

      Conic sections. (Geom.) See under Conic.

      Section liner (Drawing), an instrument to aid in drawing a series of equidistant parallel lines, -- used in representing sections.

      Thin section, a section or slice, as of mineral, animal, or vegetable substance, thin enough to be transparent, and used for study under the microscope.

      Syn: Part; portion; division.

      Usage: Section, Part. The English more commonly apply the word section to a part or portion of a body of men; as, a section of the clergy, a small section of the Whigs, etc. In the United States this use is less common, but another use, unknown or but little known in England, is very frequent, as in the phrases ``the eastern section of our country,'' etc., the same sense being also given to the adjective sectional; as, sectional feelings, interests, etc.

"divide into sections," 1819, from section (n.). Related: Sectioned; sectioning.

late 14c., "intersection of two straight lines; division of a scale;" from Old French section or directly from Latin sectionem (nominative sectio) "a cutting, cutting off, division," noun of action from past participle stem of secare "to cut," from PIE root *sek- "to cut" (cognates: Old Church Slavonic seko, sešti "to cut," se čivo "ax, hatchet;" Lithuanian isekti "to engrave, carve;" Albanian šate "mattock;" Old Saxon segasna, Old English sigðe "scythe;" Old English secg "sword," seax "knife, short sword;" Old Irish doescim "I cut;" Latin saxum "rock, stone").\n

\nFrom 1550s as "act of cutting or dividing." Meaning "subdivision of a written work, statute, etc." is from 1570s. Meaning "a part cut off from the rest" is from early 15c.

n. 1 A cutting; a part cut out from the rest of something. 2 A part, piece, subdivision of anything. vb. 1 To cut, divide or separate into pieces. 2 (context British English) To commit (a person, to a hospital, with or without their consent), as for mental health reasons. (non-gloss definition: So called after various sections of legal acts regarding mental health.)

1. n. a self-contained part of a larger composition (written or musical); "he always turns first to the business section"; "the history of this work is discussed in the next section" [syn: subdivision]

2. a very thin slice (of tissue or mineral or other substance) for examination under a microscope; "sections from the left ventricle showed diseased tissue"

3. a distinct region or subdivision of a territorial or political area or community or group of people; "no section of the nation is more ardent than the South"; "there are three synagogues in the Jewish section"

4. one of several parts or pieces that fit with others to constitute a whole object; "a section of a fishing rod"; "metal sections were used below ground"; "finished the final segment of the road" [syn: segment]

5. a small team of policemen working as part of a police platoon

6. one of the portions into which something is regarded as divided and which together constitute a whole; "the written part of the exam"; "the finance section of the company"; "the BBC's engineering division" [syn: part, division]

7. a land unit of 1 square mile measuring 1 mile on a side

8. (geometry) the area created by a plane cutting through a solid [syn: plane section]

9. a division of an orchestra containing all instruments of the same class

10. a small army unit usually having a special function

11. a specialized division of a large organization; "you'll find it in the hardware department"; "she got a job in the historical section of the Treasury" [syn: department]

12. a segment of a citrus fruit; "he ate a section of the orange"

13. the cutting of or into body tissues or organs (especially by a surgeon as part of an operation) [syn: incision, surgical incision]

14. v. divide into segments; "segment an orange"; "segment a compound word" [syn: segment]

Section may refer to:

In biology a section ( Latin: Sectio) is a taxonomic rank that is applied differently between botany and zoology.

In archaeology a section is a view in part of the archaeological sequence showing it in the vertical plane, as a cross section, and thereby illustrating its profile and stratigraphy. This may make it easier to view and interpret as it developed over time.

A section is a military sub-subunit. It usually consists of between six and 20 personnel, and is usually an alternate name for, and equivalent to, a squad. As such two or more sections usually make up an army platoon or an air force flight.

However, in the French Army and in armies based on the French model, a section is equivalent to a platoon.

In bookbinding, section (sometimes gathering) refers to a group of bifolios, or sheets of paper, stacked together and folded in half. The term is sometimes used interchangeably with signature, though the latter technically refers only to the signature mark at the bottom of the first page of a printed section.

The section is the basic building block of codex bindings. In Western bookbinding, sections are sewn through their folds, with the sewing thread linking each section to its neighboring sections.

In U.S. land surveying under the Public Land Survey System (PLSS), a section is an area nominally , containing , with 36 sections making up one survey township on a rectangular grid.

The legal description of a tract of land under the PLSS includes the name of the state, name of the county, township number, range number, section number, and portion of a section. Sections are customarily surveyed into smaller squares by repeated halving and quartering. A quarter section is and a "quarter-quarter section" is . In 1832 the smallest area of land that could be acquired was reduced to the quarter-quarter section, and this size parcel became entrenched in American mythology. After the Civil War, Freedmen (freed slaves) were reckoned to be self-sufficient with " 40 acres and a mule." In the 20th century real estate developers preferred working with parcels. The phrases "front 40" and "back 40," referring to farm fields, indicate the front and back quarter-quarter sections of land.

One of the reasons for creating sections of was the ease of dividing into halves and quarters while still maintaining a whole number of acres. A section can be halved seven times in this way, down to a parcel, or half of a quarter-quarter-quarter section—an easily surveyed 50-square- chain (2 ha) area. This system was of great practical value on the American frontier, where surveyors often had a shaky grasp of mathematics and were required to work quickly.

A description of a quarter-quarter section in standard abbreviated form, might look like "NW 1/4, NE 1/4, Sec. 34, T.3S, R.1W, 1st P.M.". In expanded form this would read "the Northwest quarter of the Northeast quarter of Section 34 of Township 3 South, Range 1 West, first Principal Meridian".

In the mathematical field of topology, a section (or cross section) of a fiber bundle π is a continuous right inverse of the function π. In other words, if E is a fiber bundle over a base space, B :

π : E → B

then a section of that fiber bundle is a continuous map,

σ : B → E

such that

π(σ(x)) = x
for all x ∈ B.

A section is an abstract characterization of what it means to be a graph. The graph of a function g : B → Y can be identified with a function taking its values in the Cartesian product E = B × Y, of B and Y:

σ(x) = (x, g(x)) ∈ E,  σ : B → E

Let π : E → X be the projection onto the first factor: π(x, y) = x. Then a graph is any function σ for which π(σ(x)) = x.

The language of fibre bundles allows this notion of a section to be generalized to the case when E is not necessarily a Cartesian product. If π : E → B is a fibre bundle, then a section is a choice of point σ(x) in each of the fibres. The condition π(σ(x)) = x simply means that the section at a point x must lie over x . (See image.)

For example, when E is a vector bundle a section of E is an element of the vector space E lying over each point x ∈ B. In particular, a vector field on a smooth manifold M is a choice of tangent vector at each point of M: this is a section of the tangent bundle of M. Likewise, a 1-form on M is a section of the cotangent bundle.

Sections, particularly of principal bundles and vector bundles, are also very important tools in differential geometry. In this setting, the base space B is a smooth manifold M, and E is assumed to be a smooth fiber bundle over M (i.e., E is a smooth manifold and π: E → M is a smooth map). In this case, one considers the space of smooth sections of E over an open set U, denoted C(U,E). It is also useful in geometric analysis to consider spaces of sections with intermediate regularity (e.g., C sections, or sections with regularity in the sense of Hölder conditions or Sobolev spaces).

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, if present, is below the section. Sections may in turn be divided into subsections.

Sections are typically used to help organise very large genera, which may have hundreds of species. A botanist wanting to distinguish groups of species may prefer to create a taxon at the rank of section or series to avoid making new combinations, i.e. many new binomial names for the species involved.

Examples:

• Lilium section Martagon Rchb. are the Turks' cap lilies
• Plagiochila aerea Taylor is the type species of Plagiochila sect. Bursatae

In music, a section is "a complete, but not independent musical idea". Types of sections include the introduction or intro, exposition, recapitulation, verse, chorus or refrain, conclusion, coda or outro, fadeout, bridge or interlude. In sectional forms such as binary, the larger unit ( form) is built from various smaller clear-cut units (sections) in combination, analogous to stanzas in poetry or somewhat like stacking legos.

Some well known songs consist of only one or two sections, for example " Jingle Bells" commonly contains verses ("Dashing through the snow...") and choruses ("Oh, jingle bells..."). It may contain "auxiliary members" such as an introduction and/or outro, especially when accompanied by instruments (the piano starts and then: "Dashing...").

A section is, "a major structural unit perceived as the result of the coincidence of relatively large numbers of structural phenomena." An episode may also refer to a section.

A passage is a musical idea that may or may not be complete or independent. For example, fill, riff, and all sections.

Musical material is any musical idea, complete or not, independent or not, including motifs.

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 → Y and g : Y → X are morphisms whose composition f o g : Y → Y is the identity morphism on Y, then g is a section of f, and f is a retraction of g.

Every section is a monomorphism, and every retraction is an epimorphism.

In algebra the sections are also called split monomorphisms and the retractions split epimorphisms. In an abelian category, if f : X → Y is a split epimorphism with split monomorphism g : Y → X, then X is isomorphic to the direct sum of Y and the kernel of f.

In books and documents, a section is a subdivision, especially of a chapter.

Sections are visually separated from each other with a section break, typically consisting of extra space between the sections, and sometimes also by a section heading for the latter section. They are a concern in the process of typography and pagination, where it may be desirable to have a page break follow a section break for the sake of aesthetics or readability.

In fiction, sections often represent scenes, and accordingly the space separating them is sometimes also called a scene break.

The section of an Alpine club (or that of any such Alpine society or association) is an independent club or society that, together with the other sections, forms the main organisation ("Alpine club"). Membership of an Alpine club is normally only possible through membership of a section. The task of an Alpine club section is the maintenance of tradition and culture, the Alpine training of its members, the planning and implementation of mountain tours and expeditions, and also the maintenance of huts and trails in the mountains. Many sections own Alpine club huts. After the initial task of the Alpine clubs - i.e. the development of the Alps for tourism and Alpinism, was considered as largely completed in Central Europe today, the work of the sections moved increasingly into the service sector, including the organization of Alpine courses and tours as well as sponsoring climbing gyms.

• The German Alpine Club consists of 354 legally independent sections with a total of ca. 815,000 members (as at January 2009). These are distributed all over Germany, the number and geographical density of the sections increasing markedly from north to south: for example, whilst there us only one section ( Rostock) in post code region 17 (Neubrandenburg), there are over 20 sections in Munich. The membership numbers of Alpine club sections varies from under one hundred to several tens of thousands; the two largest German Alpine Club sections, Munich and Oberland, both resident in Munich, form a cooperative partnership (with free membership of the other section) and have together over 110,000 members. This places them just behind FC Bayern Munich as the sports club with the greatest membership in Germany.
• The Austrian Alpine Club has 196 sections with a total of 320,000 members, including a UK section (Sektion Britannia)
• The South Tyrol Alpine Club has 32 sections with a total of 42,800 members.
• The Italian Alpine Club has 487 sections and 312 sub-sections with a total of 304,000 members.
• The Swiss Alpine Club has 111 sections with a total of 111,000 members including an Association of British Members.
• The French Alpine Club has 193 sections with a total of 90,000 members.

Not all Alpine clubs have this section structure. For example, the British Alpine Club has a central organisation with no subordinate sections.

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