Index may refer to:
Arts, entertainment, and media
Fictional entities
*
Index (''A Certain Magical Index''), a character in the light novel series ''A Certain Magical Index''
* The Index, an item on a
halo megastructure in the ''Halo'' series of video games
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), 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
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
*
Bibliographic index, a regularly updated publication that lists articles, books, or other information items
*
Citation index
* The ''Index'', colloquial name for ''Germany's List of Media Harmful to Young People'', published by the
Bundesprüfstelle für jugendgefährdende Medien
*
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
*
Index (publishing), an organized list of information in a publication
*
Index (typography), a hand- or fist-shaped punctuation mark
*
Subject indexing, describing the content of a document by keywords
*
Thumb index, a round cut-out in the pages of a publication
*
Web indexing, Internet indexing
Science, technology, and mathematics
Computer science
* Index, a key in an
associative array
*
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 indexing, Internet indexing
*
Webserver 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, 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
Σ-notation of a summation
Algebra
*
Index of a subgroup, the number of a subgroup's left cosets
* Index, the degree of an
''n''th root
* Index of a
linear map, the dimension of the map's kernel minus the dimension of its cokernel
* Index of a
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
*
Dental indices, standardized scoring systems for tooth problems
*
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
*
Refractive index, a measurement of how light propagates through a material
*
Valve Index, a virtual reality headset
Other uses
* ''INDEX'', earlier name for the
Reimei satellite
*
Index:, a Danish nonprofit organization which promotes Design for Life
*
The Index (Dubai), a skyscraper
*
Index (crater), a moon crater
See also
*
Indexer (disambiguation)
*
*
{{disambiguation|geo