I is the ninth letter of the Latin alphabet. I or i may also refer to:

Language

I (pronoun) In Modern English, ''I'' is the singular, first-person pronoun. Morphology In Standard Modern English, ''I'' has five distinct word forms: * ''I'': the nominative (subjective) form **''I'' is the only pronoun form that is always capitalize ...

, the first-person singular subject pronoun in English * I (Cyrillic), a letter used in almost all ancient and modern Cyrillic alphabets * ı, dotless I, letter used in Turkish and Azerbaijani * i, close front unrounded vowel, in the International Phonetic Alphabet * ɨ,

close central unrounded vowel The close central unrounded vowel, or high central unrounded vowel, is a type of vowel sound used in some languages. The symbol in the International Phonetic Alphabet that represents this sound is , namely the lower-case letter ''i'' with a hori ...

, in the International Phonetic Alphabet * ɪ,

near-close near-front unrounded vowel The near-close front unrounded vowel, or near-high front unrounded vowel, is a type of vowel sound, used in some spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , i.e. a small capital letter ''i ...

, in the International Phonetic Alphabet *

I (kana) I (い in hiragana or イ in katakana) is one of the Japanese kana each of which represents one mora. い is based on the sōsho style of the kanji character 以, and イ is from the radical (left part) of the kanji character 伊. In the modern ...

, one of the Japanese kana that each represent one mora * I, male prefix to some

Balinese name A Balinese name is part of a system of identification used by the Balinese people and in the western parts of the neighboring island of Lombok, Indonesia. A Balinese name will have three parts: a title, a birth order name and a personal name. Balin ...

Science, technology, and mathematics

Biology

* Troponin I, one of the three troponins *

Haplogroup I (mtDNA) Haplogroup I is a human mitochondrial DNA (mtDNA) haplogroup. It is believed to have originated about 21,000 years ago, during the Last Glacial Maximum (LGM) period in West Asia (; ; ). The haplogroup is unusual in that it is now widely distribu ...

, a human mitochondrial DNA (mtDNA) haplogroup * Haplogroup I (Y-DNA), a Y-chromosomal DNA (Y-DNA) haplogroup *

Olfactory nerve The olfactory nerve, also known as the first cranial nerve, cranial nerve I, or simply CN I, is a cranial nerve that contains sensory nerve fibers relating to the sense of smell. The afferent nerve fibers of the olfactory receptor neurons tr ...

, the 1st cranial nerve in human anatomy * the Lợn Ỉ or

Vietnamese Pot-bellied Vietnamese Pot-bellied is the exonym for the Lon I ( vi, Lợn Ỉ, italic=no) or I pig, an endangered traditional Vietnamese breed of small domestic pig. The I is uniformly black and has short legs and a low-hanging belly, from which the name ...

pig

Chemistry

Iodine Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...

, symbol I, a chemical element * I,

isoleucine Isoleucine (symbol Ile or I) is an α-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH form under biological conditions), an α-carboxylic acid group (which is in the deprot ...

, an amino acid * I,

ionic strength The ionic strength of a solution is a measure of the concentration of ions in that solution. Ionic compounds, when dissolved in water, dissociate into ions. The total electrolyte concentration in solution will affect important properties such as ...

in a chemical solution * ,

Van 't Hoff factor The van 't Hoff factor (named after Dutch chemist Jacobus Henricus van 't Hoff) is a measure of the effect of a solute on colligative properties such as osmotic pressure, relative lowering in vapor pressure, boiling-point elevation and freez ...

Computing

* i, a common generic index variable often used in

program loops In computer science, control flow (or flow of control) is the order in which individual statements, instructions or function calls of an imperative program are executed or evaluated. The emphasis on explicit control flow distinguishes an ''imper ...

* <i>, an

HTML element An HTML element is a type of HTML (HyperText Markup Language) document component, one of several types of HTML nodes (there are also text nodes, comment nodes and others). The first used version of HTML was written by Tim Berners-Lee in 1993 ...

for marking italic type * .i, the common filename extension for a file that contains the output from a preprocessor * i-, a prefix for

Apple An apple is an edible fruit produced by an apple tree (''Malus domestica''). Apple fruit tree, trees are agriculture, cultivated worldwide and are the most widely grown species in the genus ''Malus''. The tree originated in Central Asia, wh ...

products e.g. iMac, iPod, iPhone * i-, an

Internet-related prefix Internet-related prefixes such as '' e-'', '' i-'', ''cyber-'', ''info-'', ''techno-'' and ''net-'' are added to a wide range of existing words to describe new, Internet- or computer-related flavors of existing concepts, often electronic products ...

used by Internet and electronic companies

Mathematics

* I, the

Roman numeral Roman numerals are a numeral system that originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers are written with combinations of letters from the Latin alphabet, eac ...

for 1 * ,

imaginary unit The imaginary unit or unit imaginary number () is a solution to the quadratic equation x^2+1=0. Although there is no real number with this property, can be used to extend the real numbers to what are called complex numbers, using addition an ...

, for which * or ,

identity matrix In linear algebra, the identity matrix of size n is the n\times n square matrix with ones on the main diagonal and zeros elsewhere. Terminology and notation The identity matrix is often denoted by I_n, or simply by I if the size is immaterial o ...

of indeterminate size (or of size ) * ,

unit interval In mathematics, the unit interval is the closed interval , that is, the set of all real numbers that are greater than or equal to 0 and less than or equal to 1. It is often denoted ' (capital letter ). In addition to its role in real analysis, ...

, which contains all real numbers from 0 to 1 inclusive * , an index variable, e. g. in a

matrix Matrix most commonly refers to: * ''The Matrix'' (franchise), an American media franchise ** ''The Matrix'', a 1999 science-fiction action film ** "The Matrix", a fictional setting, a virtual reality environment, within ''The Matrix'' (franchis ...

or for

summation In mathematics, summation is the addition of a sequence of any kind of numbers, called ''addends'' or ''summands''; the result is their ''sum'' or ''total''. Beside numbers, other types of values can be summed as well: functions, vectors, mat ...

* , the

regularized incomplete beta function In mathematics, the beta function, also called the Euler integral of the first kind, is a special function that is closely related to the gamma function and to binomial coefficients. It is defined by the integral : \Beta(z_1,z_2) = \int_0^1 t^(1 ...

(of a variable and parameters ) * , the

unit vector In mathematics, a unit vector in a normed vector space is a vector (often a spatial vector) of length 1. A unit vector is often denoted by a lowercase letter with a circumflex, or "hat", as in \hat (pronounced "v-hat"). The term ''direction vecto ...

along the ''x''-axis in Cartesian coordinates

Physics and astronomy

* , ,

electric current An electric current is a stream of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is measured as the net rate of flow of electric charge through a surface or into a control volume. The moving pa ...

* , isospin * , luminous intensity * ,

moment of inertia The moment of inertia, otherwise known as the mass moment of inertia, angular mass, second moment of mass, or most accurately, rotational inertia, of a rigid body is a quantity that determines the torque needed for a desired angular acceler ...

* ,

orbital inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Earth ...

* I (Roman number one), in the

Yerkes spectral classification scheme In astronomy, stellar classification is the classification of stars based on their stellar spectrum, spectral characteristics. Electromagnetic radiation from the star is analyzed by splitting it with a Prism (optics), prism or diffraction grati ...

, the symbol for supergiants

Telecommunication

I band (NATO) The NATO I band is the obsolete designation given to the radio frequencies from 8 000 to 10 000 MHz (equivalent to wavelengths between 3.75 and 3 cm) during the Cold War period. Since 1992 frequency allocations, allotment and assignments are ...

, the range of radio frequencies from 8 GHz to 10 GHz in the electromagnetic spectrum * I, the ITU prefix allocated to Italy in radio communication * I, in QAM modulation schemes, the in-phase communications channel

Other uses in technology

* i, a suffix unit for

video resolution The display resolution or display modes of a digital television, computer monitor or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is ...

(vertical Interlaced lines), as in 480i or 1080i * ''I'', in the

YIQ YIQ is the color space used by the analog NTSC color TV system, employed mainly in North and Central America, and Japan. ''I'' stands for ''in-phase'', while ''Q'' stands for ''quadrature'', referring to the components used in quadrature amplitud ...

colorspace commonly used with the NTSC television encoding scheme, the color-difference channel which is in-phase with the subcarrier

Arts and media

Music

* I (band), a Norwegian heavy metal band * I, a

diatonic function In music, function (also referred to as harmonic function) is a term used to denote the relationship of a chord"Function", unsigned article, ''Grove Music Online'', . or a scale degree to a tonal centre. Two main theories of tonal functions ex ...

in tonal music theory

Albums

* ''i'' (A.R. Kane album), 1989 * ''I'' (Ben Lester album), 2019 * ''I'' (Cilvaringz album), 2007 * ''I'' (Cursed album), 2003 * ''I'' (Die Krupps album), 1992 * ''I'' (Felix Jaehn album), 2018 * ''I'' (Ikimono-gakari album), 2013 * ''I'' (Jaejoong EP), 2013 * ''I'' (JonnyX and the Groadies album), 2005 * ''I'' (Juju album), 2018 * ''I'' (Kingston Wall album), 1992 * ''I'' (Kurt Nilsen album), 2003 * ''i'' (The Magnetic Fields album), 2004 * ''I'' (Meshuggah EP), 2004 * ''i'' (Misako Odani album), 1997 * ''I'' (Nightingale album), 2000 * ''I'' (Petbrick album), 2019 * ''I'' (Sahg album), 2006 * ''I'' (Taeyeon EP), 2015 * ''I'' (Xerath album), 2009 * ''I'' (soundtrack), by A. R. Rahman from the eponymous 2015 film

Songs

* "i" (Kendrick Lamar song), a 2014 song by Kendrick Lamar from his album ''To Pimp a Butterfly'' * "i" (Lil Skies song), a song 2019 by Lil Skies from his debut album ''Shelby'' * "I" (Taproot song), a 2001 song by band Taproot from their album ''Gift'' * "

I (Who Have Nothing) "I (Who Have Nothing)" (sometimes billed as "I Who Have Nothing") is an English language cover of the Italian song "''Uno dei Tanti''" (English: "One of Many"), with music by Carlo Donida and lyrics by Giulio "Mogol" Rapetti. The initial version ...

", a 1966 Ben. E. King song also recorded by Tom Jones, who used the title for one of his albums * "I", a 2003 song on '' Weather Systems'', an album by Andrew Bird * "I", a 1992 song on ''

Selected Ambient Works 85–92 ''Selected Ambient Works 85–92'' is the debut studio album by Aphex Twin, the pseudonym of British electronic musician Richard D. James. It was released on 9 November 1992 through Apollo Records, a subsidiary of Belgian label R&S Records. The ...

'', an album by Aphex Twin * "I", a 1992 song on ''

Dehumanizer ''Dehumanizer'' is the sixteenth studio album by English rock band Black Sabbath, released on June 22, 1992. It was Sabbath's first studio album in over a decade to feature vocalist Ronnie James Dio and drummer Vinny Appice, and their first ...

'', an album by Black Sabbath * "I", a 1997 song on '' Coal Chamber'', an album by Coal Chamber * "I", a 1967 song on ''

Underground Underground most commonly refers to: * Subterranea (geography), the regions beneath the surface of the Earth Underground may also refer to: Places * The Underground (Boston), a music club in the Allston neighborhood of Boston * The Underground (S ...

'', an album by The Electric Prunes * "I", a 2012 song on ''

Muse In ancient Greek religion and mythology, the Muses ( grc, Μοῦσαι, Moûsai, el, Μούσες, Múses) are the inspirational goddesses of literature, science, and the arts. They were considered the source of the knowledge embodied in the ...

'', an album by Jolin Tsai * "I", a 1981 song on ''

Music from "The Elder" ''Music from "The Elder"'' is the ninth studio album released by American rock band Kiss on the Casablanca Records label in 1981. The album marked a substantial departure from their previous output with the concept and orchestral elements. ''Mus ...

'', an album by Kiss * "I", a 1994 song on ''

Made in USA A Made in USA mark is a country of origin label affixed to homegrown, American-made products that indicates the product is "all or virtually all" domestically produced, manufactured and assembled in the United States of America. The label is regu ...

'', an album by Pizzicato Five * "I", a 1999 song on ''

Eternal Eternal(s) or The Eternal may refer to: * Eternity, an infinite amount of time, or a timeless state * Immortality or eternal life * God, the supreme being, creator deity, and principal object of faith in monotheism Comics, film and television * ...

'', an album by Samael * "I", a 2003 song on '' Winter Story'', an album by Shinhwa * "I", a 2015 song on '' I'', an EP by Taeyeon * "I", a 2016 song by Rezz * "I", a 2019 song by Hey! Say! JUMP

Other media

* ''I'' (2015 film), an Indian Tamil-language film * ''I'' (2016 film), an Iranian film * i (TV network), the former name of ION Television * ''i'' (newspaper), a British newspaper based in London * ''i'' (Portuguese newspaper), a Portuguese newspaper based in Lisbon * I, a character in the comic book series ''

Adventure into Fear ''Adventure into Fear'' is an American horror comic book series published by Marvel Comics from cover dates November 1970 through December 1975, for 31 issues. This is its trademarked cover title for all but its first nine issues, though the ser ...

'' * ''

"I" Is for Innocent ''"I" Is for Innocent'' is the ninth novel in Sue Grafton's "Alphabet" series of mystery novels and features Kinsey Millhone Kinsey Millhone is a fictional character created by the American author Sue Grafton (1940–2017) for her "alphabet mys ...

'', the ninth novel in Sue Grafton's "Alphabet mystery" series, published in 1992 * ''

I, a Man ''I, a Man'' is a 1967 American erotic drama film written, directed and filmed by Andy Warhol. It debuted at the Hudson Theatre in New York City on August 25, 1967. The film depicts the main character, played by Tom Baker, in a series of sexual en ...

'', a 1967 Andy Warhol film

Mythology

Goddess I Goddess I is the Taube's Schellhas-Zimmermann letter designation for one of the most important Maya deities: a youthful woman to whom considerable parts of the post-Classic codices are dedicated, and who equally figures in Classic Period scenes. B ...

, a Mayan deity *

Hou-i Hou Yi () is a mythological Chinese archer. He was also known as Shen Yi and simply as Yi (). He is also typically given the title of "Lord Archer". He is sometimes portrayed as a god of archery descended from heaven to aid mankind. Other times ...

, or I, a heroic archer and hunter in Chinese mythology

Vehicles

* Italy (I), in the list of international vehicle registration codes * Italy ( aircraft registration prefix) *

Mitsubishi i The is a kei car from automaker Mitsubishi Motors, first released in January 2006, twenty eight months after its debut at the 2003 Frankfurt Motor Show. It is the first four-door automobile since the 1960s to employ a " rear midship" setup w ...

, a Japanese kei car

Other uses

* i, an international symbol for visitor or tourist information; see

ISO 7001 ISO 7001 ("public information symbols") is a standard published by the International Organization for Standardization that defines a set of pictograms and symbols for public information. The latest version, ISO 7001:2007, was published in Novembe ...

* Nintendo DSi, the third model in the Nintendo DS line, released in 2008 * Nintendo DSi XL, the larger version of the DSi, released in 2009 * I, an alternative romanization of

Lee (Korean surname) Lee, Revised Romanization of Korean, I, or Yi () is the List of South Korean surnames by prevalence, second-most-common surname in Korea, behind Kim (Korean surname), Kim (김). Historically, 李 was officially written as Ni () in Korea. The ...

I-Foundation Avanti Schools Trust is the sponsor of state-funded Hindu faith schools in the United Kingdom. The I-Foundation is a Hindu and ISKCON charity in England and Wales that is the religious authority governing schools run by the Avanti Schools Trust. ...

, a charity in charge of state-funded Hindu faith schools in the United Kingdom *

Interest rate An interest rate is the amount of interest due per period, as a proportion of the amount lent, deposited, or borrowed (called the principal sum). The total interest on an amount lent or borrowed depends on the principal sum, the interest rate, th ...

(i), in economics *

Investment Investment is the dedication of money to purchase of an asset to attain an increase in value over a period of time. Investment requires a sacrifice of some present asset, such as time, money, or effort. In finance, the purpose of investing i ...

(I), in economics *

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, the military time zone code for UTC+09:00