Index vs. Indices — What's the Difference?
By Urooj Arif & Maham Liaqat — Updated on March 18, 2024
"Index" refers to a single indicator, list, or record, often used in databases, books, or financial markets, whereas "indices" is the plural form, denoting multiple such indicators or lists.
Difference Between Index and Indices
Table of Contents
ADVERTISEMENT
Key Differences
An index is a singular term that can denote various types of ordered lists or indicators, such as a bibliographical list in a book, a database lookup key, or a statistical measure representing market or economic trends. It serves as a tool for reference or measurement, simplifying the access to or understanding of complex data sets or information collections. For instance, the index of a book helps readers locate specific information quickly, and a stock market index like the Dow Jones Industrial Average provides a snapshot of market performance.
Indices, the plural form of index, refers to multiple instances of such lists, keys, or measures. When discussing more than one index, whether they are book indices, database indices, or market indices, the term "indices" is appropriate. This distinction is important in fields like finance, where analysts might compare various market indices to assess overall economic health or sector-specific trends.
While "index" sets the stage for a singular reference point or measurement tool, "indices" expands this to a broader comparison or analysis involving multiple reference points. For example, in a database context, an index might improve the efficiency of data retrieval, whereas multiple indices in the same database can optimize different types of queries.
In practical applications, the use of "index" versus "indices" depends on the context and the number of reference tools or lists being discussed. Understanding whether to use "index" or "indices" is crucial for clarity, especially in academic, technical, and professional communications.
Comparison Chart
Definition
Singular term for a reference list, measurement tool, or indicator.
Plural form of index, referring to multiple such lists or indicators.
ADVERTISEMENT
Usage
Refers to a single ordered list or indicator.
Refers to multiple lists or indicators in various contexts.
Examples
Book index, stock market index (e.g., S&P 500).
Multiple book indices, various market indices (e.g., Dow Jones, NASDAQ).
Context
Used when discussing a singular point of reference.
Used when comparing or analyzing multiple reference points.
Fields
Publishing, databases, finance, statistics.
The same fields, especially when multiple references are involved.
Compare with Definitions
Index
An alphabetical list of names, subjects, etc., with references to the places where they occur, typically found at the end of a book.
The researcher used the book's index to find the necessary information quickly.
Indices
Plural of index, referring to multiple alphabetical lists or statistical measures.
The scientist compared various indices to conduct a comprehensive study.
Index
A system or standard for measuring or comparing the value or performance of different things.
The Dow Jones Industrial Average is an index that tracks the stock performance of 30 large companies listed on stock exchanges in the United States.
Indices
Several systems or standards used for comparison or measurement.
Economists analyze multiple economic indices to assess the overall health of the economy.
Index
An indicator, sign, or measure of something.
The level of air pollution serves as an index of the environmental health of an area.
Indices
Multiple indicators used to track different aspects or sectors.
Financial analysts monitor a range of stock market indices to gauge market trends.
Index
A statistical measure of changes in a representative group of individual data points.
The consumer price index (CPI) measures the average change in prices over time that consumers pay for a basket of goods and services.
Indices
A collection of signs or measures indicating various factors or trends.
Environmental indices provide insights into the state of the ecosystem.
Index
A pointer or indicator in a database used to speed up data retrieval.
Adding an index to the database column improved the query performance significantly.
Indices
Multiple pointers or indicators in databases that enhance data retrieval efficiency.
The database administrator optimized the system by creating several indices.
Index
An alphabetized list of names, places, and subjects treated in a printed work, giving the page or pages on which each item is mentioned.
Indices
A plural of index.
Index
A thumb index.
Indices
See Index.
Index
A table, file, or catalog.
Index
(Computers) A list of keywords associated with a record or document, used especially as an aid in searching for information.
Index
Something that reveals or indicates; a sign
"Her face ... was a fair index to her disposition" (Samuel Butler).
Index
A character (☞) used in printing to call attention to a particular paragraph or section. Also called hand.
Index
An indicator or pointer, as on a scientific instrument.
Index
(Mathematics) A number or symbol, often written as a subscript or superscript to a mathematical expression, that indicates an operation to be performed, an ordering relation, or a use of the associated expression.
Index
A number derived from a formula, used to characterize a set of data.
Index
A statistical value that represents the price or value of an aggregate of goods, services, wages, or other measurable quantities in comparison with a reference number for a previous period of time.
Index
A number that represents the change in price or value of stocks or other securities in a particular market, sector, or asset class.
Index
The stocks or other securities represented by an index.
Index
Index Roman Catholic Church A list formerly published by Church authority, restricting or forbidding the reading of certain books.
Index
To furnish with an index
Index a book.
Index
To enter in an index.
Index
To indicate or signal.
Index
To adjust through indexation.
Index
An alphabetical listing of items and their location.
The index of a book lists words or expressions and the pages of the book upon which they are to be found.
Index
The index finger; the forefinger.
Index
A movable finger on a gauge, scale, etc.
Index
(typography) A symbol resembling a pointing hand, used to direct particular attention to a note or paragraph.
Index
That which points out; that which shows, indicates, manifests, or discloses.
Index
A sign; an indication; a token.
Index
(linguistics) A type of noun where the meaning of the form changes with respect to the context; e.g., 'Today's newspaper' is an indexical form since its referent will differ depending on the context. See also icon and symbol.
Index
(economics) A single number calculated from an array of prices or of quantities.
Index
(science) A number representing a property or ratio; a coefficient.
Index
(mathematics) A raised suffix indicating a power.
Index
An integer or other key indicating the location of data, e.g. within an array, vector, database table, associative array, or hash table.
Index
A data structure that improves the performance of operations on a table.
Index
(obsolete) A prologue indicating what follows.
Index
(transitive) To arrange an index for something, especially a long text.
MySQL does not index short words and common words.
Index
To inventory; to take stock.
Index
To normalise in order to account for inflation; to correct for inflation by linking to a price index in order to maintain real levels.
Index
To measure by an associated value.
Index
To be indexical for (some situation or state of affairs); to indicate.
Index
(computing) To access a value in a data container by an index.
Index
That which points out; that which shows, indicates, manifests, or discloses; as, the increasing unemployment rate is an index of how much the economy has slowed.
Tastes are the indexes of the different qualities of plants.
Index
That which guides, points out, informs, or directs; a pointer or a hand that directs to anything, as the hand of a watch, a movable finger or other form of pointer on a gauge, scale, or other graduated instrument.
Index
A table for facilitating reference to topics, names, and the like, in a book, usually giving the page on which a particular word or topic may be found; - usually alphabetical in arrangement, and printed at the end of the volume. Typically found only in non-fiction books.
Index
A prologue indicating what follows.
Index
The second finger, that next to the pollex (thumb), in the manus, or hand; the forefinger; index finger.
Index
The figure or letter which shows the power or root of a quantity; the exponent.
Index
The ratio, or formula expressing the ratio, of one dimension of a thing to another dimension; as, the vertical index of the cranium.
Index
A number providing a measure of some quantity derived by a formula, usually a form of averaging, from multiple quantities; - used mostly in economics; as, the index of leading indicators; the index of industrial production; the consumer price index. See, for example, the consumer price index.
Index
A file containing a table with the addresses of data items, arranged for rapid and convenient search for the addresses.
Index
A number which serves as a label for a data item and also represents the address of a data item within a table or array.
Index
The Index prohibitorius, a catalogue of books which are forbidden by the church to be read; also called Index of forbidden books and Index Librorum Prohibitorum.
Index
To provide with an index or table of references; to put into an index; as, to index a book, or its contents.
Index
To adjust (wages, prices, taxes, etc.) automatically so as to compensate for changes in prices, usually as measured by the consumer price index or other economic measure. Its purpose is usually to copensate for inflation.
Index
To insert (a word, name, file folder, etc.) into an index or into an indexed arrangement; as, to index a contract under its date of signing.
Index
A numerical scale used to compare variables with one another or with some reference number
Index
A number or ratio (a value on a scale of measurement) derived from a series of observed facts; can reveal relative changes as a function of time
Index
A mathematical notation indicating the number of times a quantity is multiplied by itself
Index
An alphabetical listing of names and topics along with page numbers where they are discussed
Index
The finger next to the thumb
Index
List in an index
Index
Provide with an index;
Index the book
Index
Adjust through indexation;
The government indexes wages and prices
Common Curiosities
When should I use "index" instead of "indices"?
Use "index" when referring to a single list, tool, or indicator. "Indices" should be used when discussing more than one.
What are indices?
Indices is the plural form of index, denoting multiple such lists, tools, or indicators in various contexts.
Can "indexes" be used instead of "indices"?
Yes, "indexes" is an alternative plural form of "index," though "indices" is often preferred in formal and academic contexts.
What is an index?
An index is a singular term referring to an ordered list, measurement tool, or indicator used for reference, comparison, or data retrieval.
How do database indices work?
Database indices function as internal data structures that improve the speed of data retrieval operations by effectively pointing to the data location within a database.
How does an index function in a book?
In a book, an index is a list at the end that provides references to the pages where specific subjects, names, or terms can be found.
What role do indices play in the financial market?
Indices in financial markets serve as benchmarks for tracking the performance of specific sectors or the market as a whole.
Are indices only used in finance?
No, indices are used in various fields, including academia, information technology, and environmental science, to measure, compare, and analyze different sets of data.
Why is it important to distinguish between index and indices?
Distinguishing between the two ensures clarity and precision in communication, especially in fields like finance, statistics, and information technology.
Can the term "index" refer to something other than a list in a book?
Yes, "index" can refer to various indicators or measurement tools in fields like statistics, finance, and information technology, beyond just a bibliographic list in a book.
Share Your Discovery
Previous Comparison
Stairway vs. Staircase
Next Comparison
Toke vs. TookAuthor Spotlight
Written by
Urooj ArifUrooj is a skilled content writer at Ask Difference, known for her exceptional ability to simplify complex topics into engaging and informative content. With a passion for research and a flair for clear, concise writing, she consistently delivers articles that resonate with our diverse audience.
Co-written by
Maham Liaqat
