In general, a node is a localized swelling (a "

knot A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ' ...

") or a point of intersection (a

vertex Vertex, vertices or vertexes may refer to: Science and technology Mathematics and computer science *Vertex (geometry), a point where two or more curves, lines, or edges meet * Vertex (computer graphics), a data structure that describes the positio ...

). Node may refer to:

In mathematics

Vertex (graph theory) In discrete mathematics, and more specifically in graph theory, a vertex (plural vertices) or node is the fundamental unit of which graphs are formed: an undirected graph consists of a set of vertices and a set of edges (unordered pairs of ve ...

, a vertex in a mathematical graph *

Vertex (geometry) In geometry, a vertex (in plural form: vertices or vertexes) is a point where two or more curves, lines, or edges meet. As a consequence of this definition, the point where two lines meet to form an angle and the corners of polygons and polyh ...

, a point where two or more curves, lines, or edges meet. * Node (autonomous system), behaviour for an ordinary differential equation near a critical point *

Singular point of an algebraic variety In the mathematical field of algebraic geometry, a singular point of an algebraic variety is a point that is 'special' (so, singular), in the geometric sense that at this point the tangent space at the variety may not be regularly defined. In cas ...

, a type of singular point of a curve

In science and engineering

Astronomy

Orbital node An orbital node is either of the two points where an orbit intersects a plane of reference to which it is inclined. A non-inclined orbit, which is contained in the reference plane, has no nodes. Planes of reference Common planes of referen ...

, the points where an orbit crosses a plane of reference ** Lunar node, where the orbits of the sun and moon intersect ** Longitude of the ascending node, how orbital nodes are parameterized

Biology

* Lymph node, an immune system organ used to store white blood cells *

Node of Ranvier In neuroscience and anatomy, nodes of Ranvier ( ), also known as myelin-sheath gaps, occur along a myelinated axon where the axolemma is exposed to the extracellular space. Nodes of Ranvier are uninsulated and highly enriched in ion channels, al ...

, periodic gaps in the insulating myelin sheaths of myelinated axons *

Sinoatrial node The sinoatrial node (also known as the sinuatrial node, SA node or sinus node) is an oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of cells known as pacemaker cells. The sinus node is approxima ...

and

atrioventricular node The atrioventricular node or AV node electrically connects the heart's atria and ventricles to coordinate beating in the top of the heart; it is part of the electrical conduction system of the heart. The AV node lies at the lower back section of t ...

, specialized tissues in the heart responsible for initiating and coordinating the heartbeat * Primitive knot or primitive node, the organizer tissue for gastrulation in vertebrates *The place on a

plant stem A stem is one of two main structural axes of a vascular plant, the other being the root. It supports leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, stores nut ...

where a leaf is attached *In

Cladistics Cladistics (; ) is an approach to biological classification in which organisms are categorized in groups (" clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is typically shared derived cha ...

, a shared ancestor (also see Clade)

Computing and electronics

Node (networking) In telecommunications networks, a node (, ‘knot’) is either a redistribution point or a communication endpoint. The definition of a node depends on the network and protocol layer referred to. A physical network node is an electronic devic ...

, a point of connection in a communication network *An entity in a mesh network *

Node (circuits) In electrical engineering, a node is any region on a circuit between two Electrical element, circuit elements. In Circuit diagram, circuit diagrams, connections are ideal wires with zero resistance, so a node consists of the entire section of wire ...

, a region in an electrical circuit where there is no change in potential *

Node (computer science) A node is a basic unit of a data structure, such as a linked list or tree data structure. Nodes contain data and also may link to other nodes. Links between nodes are often implemented by pointers. Nodes and Trees Nodes are often arranged int ...

, a basic unit used to build data structures * Goal node (computer science), a node in a graph that meets defined criteria for success or termination * Node (UML), the representation of a computational device in the Unified Modeling Language *

Node.js Node.js is an open-source server environment. Node.js is cross-platform and runs on Windows, Linux, Unix, and macOS. Node.js is a back-end JavaScript runtime environment. Node.js runs on the V8 JavaScript Engine and executes JavaScript code o ...

, a JavaScript-based, cross-platform runtime environment * NodeB, hardware that is connected to the mobile phone network * NODE (wireless sensor), a wireless handheld sensor for smart devices *Node, a shorthand used to designate a semiconductor fabrication process

Linguistics

* Node (linguistics), a branch point in the

Tree model In historical linguistics, the tree model (also Stammbaum, genetic, or cladistic model) is a model of the evolution of languages analogous to the concept of a family tree, particularly a phylogenetic tree in the biological evolution of species. ...

, or Node Theory, of language evolution

Physics

Node (physics) A node is a point along a standing wave where the wave has minimum amplitude. For instance, in a vibrating guitar string, the ends of the string are nodes. By changing the position of the end node through frets, the guitarist changes the effect ...

, a point along a standing wave where the wave has minimal amplitude

Space-station modules

Unity (ISS module) upright=1.0, The ''Unity'' module as seen in May 2011 The ''Unity'' connecting module, also known as Node 1, is the first U.S.-built component of the International Space Station (ISS). It connects the Russian and United States segments of t ...

or Node 1, one of the first modules of the International Space Station *

Harmony (ISS module) ''Harmony'', also known as ''Node 2'', is the "utility hub" of the International Space Station. It connects the laboratory modules of the United States, Europe and Japan, as well as providing electrical power and electronic data. Sleeping cab ...

or Node 2, module of the International Space Station *

Tranquility (ISS module) ''Tranquility'', also known as Node 3, is a module of the International Space Station (ISS). It contains environmental control systems, life support systems, a toilet, exercise equipment, and an observation Cupola (ISS module), cupola. The Eu ...

or Node 3, a module of the International Space Station with the Cupola * Node 4, a proposed module of the International Space Station * ''

Prichal (ISS module) ''Prichal'' nodal module also known as Uzlovoy Module or UM (russian: Узловой Модуль "Причал", ''Nodal Module Berth'') is a Russian spacecraft which is part of the International Space Station (ISS). It was approved in 201 ...

'', a planned module of the International Space Station to be launched in 2021

In music

* Node (band), Italian death metal band *

Node (singer) Rijan Nabaz better known by his stage name Node (born 3 March 1990) is a Danish-Kurdish singer and rapper. He started in 2012 as a pop singer under the mononym Rijan releasing his song "Ligeglad". Very early on he recorded also the song "Farvel ...

, Danish singer and hip hop artist of Kurdish origin * ''Node'' (album), a 2015 album by Australian metalcore band Northlane

Other uses

* Node, Kentucky *

Node tribe The Node community ( sd, نُود), also known as Nodi or Nodhi, is a Muslim community primarily found in the state of Gujarat in India and the province of Sindh in Pakistan. They are one of several pastoral nomadic communities inhabiting the Bann ...

, a community of pastoral nomads in India and Pakistan *

Node In general, a node is a localized swelling (a "knot") or a point of intersection (a vertex). Node may refer to: In mathematics * Vertex (graph theory), a vertex in a mathematical graph *Vertex (geometry), a point where two or more curves, lines ...

, a transport hub in a transportation system * Giordana Racing Team, a British cycling team, formerly named Node4-Giordana *'' Node Magazine'', a literary project based on the novel '' Spook Country'' by

William Gibson William Ford Gibson (born March 17, 1948) is an American-Canadian speculative fiction writer and essayist widely credited with pioneering the science fiction subgenre known as ''cyberpunk''. Beginning his writing career in the late 1970s, hi ...

*''New Oxford Dictionary of English'', a single-volume English language dictionary, see Oxford Dictionary of English *Node, a cyborg with a donated human face used as a guide, in "

Silence in the Library "Silence in the Library" is the eighth episode of the fourth series of the revived British science fiction television series '' Doctor Who''. It was first broadcast on BBC One on 31 May 2008. It is the first of a two-part story; the second part, ...

" (''Doctor Who'') *Node, the pommel-like part of a

chalice A chalice (from Latin 'mug', borrowed from Ancient Greek () 'cup') or goblet is a footed cup intended to hold a drink. In religious practice, a chalice is often used for drinking during a ceremony or may carry a certain symbolic meaning. R ...

where the stem meets the cup *A nodal organizational structure, such as in terms of business management, see Cellular organizational structure