B is the second letter of the Latin alphabet. B may also refer to:

Science, technology, and mathematics

Astronomy

* Astronomical objects in the Barnard list of dark nebulae (abbreviation B) * Latitude (''b'') in the

galactic coordinate system The galactic coordinate system is a celestial coordinate system in spherical coordinates, with the Sun as its center, the primary direction aligned with the approximate center of the Milky Way Galaxy, and the fundamental plane (spherical coordin ...

Biology and medicine

* Haplogroup B (mtDNA), a human mitochondrial DNA (mtDNA) haplogroup * Haplogroup B (Y-DNA), a Y-chromosomal DNA (Y-DNA) haplogroup * Blood type B * ATC code B ''Blood and blood forming organs'', a section of the Anatomical Therapeutic Chemical Classification System *

Vitamin B B vitamins are a class of water-soluble vitamins that play important roles in cell metabolism and synthesis of red blood cells. They are a chemically diverse class of compounds. Dietary supplements containing all eight are referred to as a vita ...

Hepatitis B Hepatitis B is an infectious disease caused by the '' hepatitis B virus'' (HBV) that affects the liver; it is a type of viral hepatitis. It can cause both acute and chronic infection. Many people have no symptoms during an initial infection. ...

* Berlin Botanical Garden and Botanical Museum, assigned the abbreviation B as a repository of herbarium specimens

Computing

B (programming language) B is a programming language developed at Bell Labs circa 1969 by Ken Thompson and Dennis Ritchie. B was derived from BCPL, and its name may possibly be a contraction of BCPL. Thompson's coworker Dennis Ritchie speculated that the name might ...

B-Method The B method is a method of software development based on B, a tool-supported formal method based on an abstract machine notation, used in the development of computer software. Overview B was originally developed in the 1980s by Jean-Raymond Abr ...

, for computer software development *

B-tree In computer science, a B-tree is a self-balancing tree data structure that maintains sorted data and allows searches, sequential access, insertions, and deletions in logarithmic time. The B-tree generalizes the binary search tree, allowing fo ...

, a data structure *

Bit The bit is the most basic unit of information in computing and digital communication. The name is a portmanteau of binary digit. The bit represents a logical state with one of two possible values. These values are most commonly represented as ...

(b) *

Byte The byte is a unit of digital information that most commonly consists of eight bits. Historically, the byte was the number of bits used to encode a single character of text in a computer and for this reason it is the smallest addressable un ...

(B) * , 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 199 ...

denoting bold text

Physical and chemical quantities and units

* One of the

reciprocal lattice Reciprocal lattice is a concept associated with solids with translational symmetry which plays a major role in many areas such as X-ray and electron diffraction as well as the energies of electrons in a solid. It emerges from the Fourier tran ...

vectors (''b*'') * Breadth (''b''); see

length Length is a measure of distance. In the International System of Quantities, length is a quantity with Dimension (physical quantity), dimension distance. In most systems of measurement a Base unit (measurement), base unit for length is chosen, ...

Impact parameter In physics, the impact parameter is defined as the perpendicular distance between the path of a projectile and the center of a potential field created by an object that the projectile is approaching (see diagram). It is often referred to in ...

(''b'') *

Molality In chemistry, molality is a measure of the amount of solute in a solution relative to a given mass of solvent. This contrasts with the definition of '' molarity'' which is based on a given volume of solution. A commonly used unit for molality ...

(''b'') *

Barn (unit) A barn (symbol: b) is a metric unit of area equal to (100 fm2). This is equivalent to a square that is (10 fm) each side, or a circle of diameter approximately (11.28 fm). Originally used in nuclear physics for expressing th ...

(b), a unit of area *

Magnetic field A magnetic field (sometimes called B-field) is a physical field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular ...

(''B'') * Napierian

absorbance Absorbance is defined as "the logarithm of the ratio of incident to transmitted radiant power through a sample (excluding the effects on cell walls)". Alternatively, for samples which scatter light, absorbance may be defined as "the negative log ...

(''B'') *

Rotational constant In rotordynamics, the rigid rotor is a mechanical model of rotating systems. An arbitrary rigid rotor is a 3-dimensional rigid object, such as a top. To orient such an object in space requires three angles, known as Euler angles. A special r ...

(''B'') * Second

virial coefficient Virial coefficients B_i appear as coefficients in the virial expansion of the pressure of a many-particle system in powers of the density, providing systematic corrections to the ideal gas law. They are characteristic of the interaction potenti ...

(''B'') *

Susceptance In electrical engineering, susceptance () is the imaginary part of admittance (), where the real part is conductance (). The reciprocal of admittance is impedance (), where the imaginary part is reactance () and the real part is resistance ( ...

(''B'') * Bel (''B''), a logarithmic unit equal to ten

decibel The decibel (symbol: dB) is a relative unit of measurement equal to one tenth of a bel (B). It expresses the ratio of two values of a Power, root-power, and field quantities, power or root-power quantity on a logarithmic scale. Two signals whos ...

Other uses in science, technology, and mathematics

* ''B'', a

modal logic Modal logic is a kind of logic used to represent statements about Modality (natural language), necessity and possibility. In philosophy and related fields it is used as a tool for understanding concepts such as knowledge, obligation, and causality ...

bottom quark The bottom quark, beauty quark, or b quark, is an elementary particle of the third generation. It is a heavy quark with a charge of − ''e''. All quarks are described in a similar way by electroweak interaction and quantum chromodynamic ...

(symbol: b), an

elementary particle In particle physics, an elementary particle or fundamental particle is a subatomic particle that is not composed of other particles. The Standard Model presently recognizes seventeen distinct particles—twelve fermions and five bosons. As a c ...

B meson In particle physics, B mesons are mesons composed of a bottom antiquark and either an up (), down (), strange () or charm quark (). The combination of a bottom antiquark and a top quark is not thought to be possible because of the top quark' ...

, a type of meson *

Boolean domain In mathematics and abstract algebra, a Boolean domain is a set consisting of exactly two elements whose interpretations include ''false'' and ''true''. In logic, mathematics and theoretical computer science, a Boolean domain is usually written ...

(

\mathbb

), in mathematics *

Boron Boron is a chemical element; it has symbol B and atomic number 5. In its crystalline form it is a brittle, dark, lustrous metalloid; in its amorphous form it is a brown powder. As the lightest element of the boron group it has three ...

, symbol B, a chemical element *

Bulb (photography) The Bulb setting (abbreviated B) on camera shutters is a momentary-action mode that holds shutters open for as long as a photographer depresses the shutter-release button. The Bulb setting is distinct from shutter's Time (T) setting, which is ...

, a shutter-speed setting * B battery, a battery used to provide the plate voltage of a

vacuum tube A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It ...

* B horizon, a layer of soil commonly known as subsoil * B, B+ and B−, expressions of buoyancy in convective available potential energy

Linguistics

* В, a letter of the Cyrillic alphabet *

Voiced bilabial stop The voiced bilabial plosive or stop is a type of consonantal sound used in many spoken languages. The symbol in the International Phonetic Alphabet that represents this sound is , and the equivalent X-SAMPA symbol is b. The voiced bilabial stop oc ...

(b, in the International Phonetic Alphabet)

Arts and media

Music

Musical notation

B (musical note) B, also known as Si, Ti, or, in some European countries, H, is the seventh note and the twelfth semitone of the fixed-Do solfège. Its enharmonic equivalents are C (C-flat) and A (A-double sharp). When calculated in equal temperament with a ...

B major B major is a major scale based on B. The pitches B, C, D, E, F, G, and A are all part of the B major scale. Its key signature has five sharps. Its relative minor is G-sharp minor, its parallel minor is B minor, and its enharmonic equi ...

, a scale *

B minor B minor is a minor scale based on B, consisting of the pitches B, C, D, E, F, G, and A. Its key signature has two sharps. Its relative major is D major and its parallel major is B major. The B natural minor scale is: Changes need ...

, a scale * B major chord,

Chord names and symbols (popular music) Musicians use various kinds of chord names and symbols in different contexts to represent musical chords. In most genres of popular music, including jazz, pop, and rock, a chord name and its corresponding symbol typically indicate one or mo ...

Flat (music) In music, flat means lower in pitch. It may either be used in a general sense to mean any lowering of pitch, or to specifically refer to lowering pitch by a semitone. A flat is the opposite of a sharp () which indicates a raised pitch in the sa ...

, a note lower in pitch by a semitone

Performers

Beyoncé Beyoncé Giselle Knowles-Carter ( ; born September 4, 1981) is an American singer, songwriter, actress, and businesswoman. With a career spanning over three decades, she has established herself as one of the most Cultural impact of Beyoncé, ...

* B, member of Superorganism (band)

Recordings

* ''B'' (BamBam EP), an extended play by BamBam * ''B'' (Battles EP), an extended play by Battles * ''B'' (I Am Kloot album), a compilation album by I Am Kloot * ''b'' (Moxy Früvous EP), an extended play by Moxy Früvous * "b", an

Iamamiwhoami iamamiwhoami ( ) is an electronic music and audiovisual project led by Swedish singer-songwriter Jonna Lee (singer), Jonna Lee in collaboration with producer Claes Björklund. Since 2009, the project has released a series of audiovisual works ...

song * "B", a song by Todrick Hall from his 2018 album '' Forbidden''

Other media

* /b/, a board on 4chan * ''b'' (newspaper), a free daily, tabloid sized newspaper, published by ''The Baltimore Sun'' * ''

Codex Vaticanus Graecus 1209 The Codex Vaticanus (Vatican Library, The Vatican, Vatican Library, Bibl. Vat., Vat. gr. 1209), is a manuscript of the Greek Bible, containing the majority of the Old Testament and the majority of the New Testament. It is designated by Scribal ab ...

'', an ancient bible * Rajawali Televisi, previously named B Channel, a television channel in Indonesia * B, the production code for the 1963–64 ''Doctor Who'' serial ''

The Daleks ''The Daleks'' (also known as ''The Mutants'' and ''The Dead Planet'' is the second serial in the British science fiction television series ''Doctor Who'', which was first broadcast on BBC TV in seven weekly parts from 21 December 1963 to ...

'' * B, a character in '' Total Drama: Revenge of the Island'' * '' "B" Is for Burglar'', the second novel in Sue Grafton's ''Alphabet Mystery'' series, published in 1985

Places

* Belgium, on the vehicle registration plates of the European Union * Bucharest, on the

vehicle registration plates of Romania The most common format for vehicle registration plates in Romania consists of black letters on white background in the format CC 12 ABC, where CC is a two letter county code, 12 is a two digit group, and ABC is a three letter group. ...

Sport

* Australian rules football positions#Full back, in Australian Rules football * B, often used after the name of football clubs to denote a

reserve team In sports, a reserve team is a team composed of players who are under contract to a club but who do not regularly play in matches for the club's primary team. Reserve teams usually include players who are part of the larger first-team squad but ...

Transportation

B (New York City Subway service) The B Sixth Avenue Express is a rapid transit service in the B Division (New York City Subway), B Division of the New York City Subway. Its route emblem, or "bullet", is colored , since it uses the IND Sixth Avenue Line in Midtown Manhattan. T ...

B Line (Los Angeles Metro) The B Line (formerly the Red Line from 1993–2020) is a fully underground rapid transit line operating in Los Angeles, running between North Hollywood, Los Angeles, North Hollywood and Los Angeles Union Station, Union Station in Downtown Los ...

* Line B (Buenos Aires Metro) * B (S-train), in Copenhagen *

RER B RER B is one of the five lines in the Réseau Express Régional (English: Regional Express Network), a hybrid commuter rail and rapid transit system serving Paris, France and its Île-de-France suburbs. The RER B line crosses the region from no ...

, a line in the RER of Paris * The West Japan Railway Company service symbol for: ** Kosei Line ** Inbi Line ** Kabe Line *

Bundesstraße ''Bundesstraße'' (, ), abbreviated ''B'', is the denotation for German and Austrian national highways. Germany Germany's ''Bundesstraßen'' network has a total length of about 40,000 km. German ''Bundesstraßen'' are labelled with re ...

(federal highway) in Austria and Germany (abbreviation B) *

Bayshore Route The signed as Route B, is one of the routes of the Toll road, tolled Shuto Expressway system in the Greater Tokyo Area. The Bayshore Route is a stretch of toll highway that runs from the Kanazawa-ku, Yokohama, Kanazawa ward of Yokohama in th ...

of Shuto Expressway in Japan, numbered as route B * Mexico City Metro Line B

Other uses

* B (grade), for evaluation of students' work * B (bank), a banking brand in the United Kingdom *

Barnabites The Barnabites (), officially named as the Clerics Regular of Saint Paul (), are a religious order of clerics regular founded in 1530 in the Catholic Church. They are associated with the Angelic Sisters of Saint Paul and the members of the Ba ...

(), a religious order abbreviated to the postnominal ''B.'' * Bravo, the military time zone code for UTC+02:00 *

Brutus Marcus Junius Brutus (; ; 85 BC – 23 October 42 BC) was a Roman politician, orator, and the most famous of the assassins of Julius Caesar. After being adopted by a relative, he used the name Quintus Servilius Caepio Brutus, which was reta ...

, a Roman cognomen (abbreviation B) * Farmall B, a tractor produced by International Harvester from 1939 to 1947 * Dominical letter B for a

common year starting on Saturday A common year starting on Saturday is any non-leap year (i.e. a year with 365 days) that begins on Saturday, 1 January, and ends on Saturday, 31 December. Its dominical letter hence is B. The most recent year of such kind was 2022, and the next ...

* B, a soft grade of

pencil lead A pencil () is a writing or drawing implement with a solid pigment core in a protective casing that reduces the risk of core breakage and keeps it from marking the user's hand. Pencils create marks by physical abrasion (mechanical), abrasi ...