Index

{{for|Wikipedia’s index|Wikipedia:Index|selfref=y}} {{wiktionary|Index|index|indexes|indice|indices}} '''Index''' ({{plural form}}: '''indexes''' or '''indices''') most commonly refers to: * [[Index (publishing)]], an organized list of information in a publication * [[Web indexing]], Internet indexing * An index, a key in an [[associative array]] Index may also refer to: {{tocright}} ==Arts, entertainment, and media== ===Fictional entities=== * [[Index (A Certain Magical Index)|Index (''A Certain Magical Index'')]], a character in the light novel series ''A Certain Magical Index'' * The Index, an item on the [[Halo Array]] in the ''Halo'' video game series

===Periodicals and news portals=== * ''[[Index Magazine]]'', a publication for art and culture * [[Index.hr]], a Croatian online newspaper * [[index.hu]], a Hungarian-language news and community portal * [[The Index (Kalamazoo College)|''The Index'' (Kalamazoo College)]], a student newspaper * ''The Index'', an 1860s European propaganda journal created by [[Henry Hotze]] to support the Confederate States of America * ''[[Truman State University Index]]'', a student newspaper * ''The Index: A Weekly Paper Devoted to Free Religion'' (1870–1886), the semi-official periodical of the [[Free Religious Association]]

===Other arts, entertainment and media=== * [[The Index (band)]] * ''Indexed'', a Web cartoon by [[Jessica Hagy]] * ''Index'', album by [[Ana Mena]]

== Business enterprises and events == * [[Index (retailer)]], a former UK catalogue retailer * [[INDEX]], a market research fair in Lucknow, India * [[Index Corporation]], a Japanese video game developer

==Finance== * [[Index fund]], a collective investment scheme * [[Stock market index]], a statistical average of prices of selected securities

==Places in the United States== * [[Index, Arkansas]], an unincorporated community * [[Index, Kentucky]], an unincorporated community * [[Index, Missouri]], a ghost town * [[Index, New York]], a hamlet in Hartwick and Otsego, New York * [[Index, Virginia]], an unincorporated community * [[Index, Washington]], a town * [[Index, West Virginia]], an unincorporated community

==Publishing and library studies== * [[Index (typography)]], a hand- or fist-shaped punctuation mark * [[Bibliographic index]], a regularly updated publication that lists articles, books, or other information items * [[Citation index]] * The ''Index'', colloquial name for the ''[[Federal Agency for Child and Youth Protection in the Media#List of Media Harmful to Youth and Adolescents|List of Media Harmful to Youth and Adolescents]]'' (Germany) * [[Index card]], used for recording and storing small amounts of data * ''[[Index Librorum Prohibitorum]]'', a list of publications which the Catholic Church censored * [[Index on Censorship]], a publishing organization that campaigns for freedom of expression, or its magazine of the same name * [[Subject indexing]], describing the content of a document by keywords * [[Thumb index]], a round cut-out in the pages of a publication

==Science, technology, and mathematics== ===Computer science=== * [[Index (typography)]], a character in Unicode, its code is 132 * Index, the dataset maintained by [[search engine indexing]] * [[Array index]], an integer pointer into an array data structure * [[BitTorrent index]], a list of .torrent files available for searches * [[Database index]], a data structure that improves the speed of data retrieval * [[Index mapping]] of raw data for an array * [[Index register]], a processor register used for modifying operand addresses during the run of a program * [[Indexed color]], in computer imagery * [[Indexed Sequential Access Method]] (ISAM), used for indexing data for fast retrieval * [[Lookup table]], a data structure used to store precomputed information * [[Site map]], or site index, a list of pages of a web site accessible to crawlers or users * [[Web server directory index]], a default or index web page in a directory on a web server, such as index.html

===Economics=== * [[Index (economics)]], a single number calculated from an array of prices and quantities ** [[Price index]], a typical price for some good or service

===Mathematics and statistics=== * Index, the position of an element in a [[sequence]] * Index, a number or other symbol that specifies an element of an [[indexed family]] or set * Index, an element of an [[index set]] * Index, the label of a summand in [[sigma notation|Σ-notation]] of a summation

==== Algebra ==== * [[Index of a subgroup]], the number of a subgroup's left cosets * Index, the degree of an [[nth root|''n''th root]] * Index of a [[linear map#Index|linear map]], the dimension of the map's kernel minus the dimension of its cokernel * Index of a [[Matrix (mathematics)|matrix]] * Index of a real [[quadratic form]]

==== Analysis ==== * Index, the [[winding number]] of an oriented closed curve on a surface relative to a point on that surface * [[Diversity index]], a measure of distribution or variety in fields such as ecology or information science * [[Index of a vector field]], an integer that helps to describe the behaviour of a vector field around an isolated zero

==== Number theory ==== * Index, or the [[discrete logarithm]] of a number

====Statistics==== * [[Index (statistics)]], a type of aggregate measure ** [[Scale (social sciences)]], a method of reporting data in social sciences, sometimes called an index

===Other uses in science and technology=== * [[Indexicality]], in linguistics, the phenomenon of a sign pointing to some object in the context in which it occurs * [[Indexing (motion)]], in mechanical engineering and machining, movement to a precisely known location * [[Index (physical sciences)]], a synonym for ratio

==Other uses== * ''INDEX'', earlier name for the [[Reimei]] satellite * [[Index:]], a Danish nonprofit organization that promotes Design for Life * [[The Index (Dubai)]], a skyscraper * [[Index (crater)]], a Moon crater * In [[semiotics]], an unintentional and non-arbitrary sign causally related to what it indicates, for example the smoke from a fire or the footprint of an animal.

==See also== * [[Indexi]], a Yugoslav rock band * [[Indexer (disambiguation)]] * [[Directory (disambiguation)]] * {{Look from}} * {{In title}}