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

knot A knot is an intentional complication in Rope, cordage which may be practical or decorative, or both. Practical knots are classified by function, including List of hitch knots, hitches, List of bend knots, bends, List of loop knots, loop knots, ...

") or a point of intersection (a vertex). 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 (: vertices or vertexes), also called a corner, is a point (geometry), point where two or more curves, line (geometry), lines, or line segments Tangency, meet or Intersection (geometry), intersect. For example, the point wh ...

, 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 ca ...

, a type of singular point of a curve

In science and engineering

Spherical geometry

* node, the points where a

great circle In mathematics, a great circle or orthodrome is the circular intersection of a sphere and a plane passing through the sphere's center point. Discussion Any arc of a great circle is a geodesic of the sphere, so that great circles in spher ...

crosses a plane of reference, or the equator of a sphere

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 referenc ...

, the points where an orbit crosses a plane of reference **

Lunar node A lunar node is either of the two orbital nodes of the Moon; that is, the two points at which the orbit of the Moon intersects the ecliptic. The ''ascending'' (or ''north'') node is where the Moon moves into the northern ecliptic hemisphere, ...

, where the orbits of the Sun and Moon intersect ** Longitude of the ascending node, how orbital nodes are parameterized

Biology

Lymph node A lymph node, or lymph gland, is a kidney-shaped organ of the lymphatic system and the adaptive immune system. A large number of lymph nodes are linked throughout the body by the lymphatic vessels. They are major sites of lymphocytes that includ ...

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

Node of Ranvier 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 axonal domains that are high in sodium and potassium ion channels co ...

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

Sinoatrial node The sinoatrial node (also known as the sinuatrial node, SA node, sinus node or Keith–Flack node) is an ellipse, oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of Cell (biology), cells known as pa ...

and

atrioventricular node The atrioventricular node (AV node, or Aschoff-Tawara 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 ...

, 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 leaf, leaves, flowers and fruits, transports water and dissolved substances between the roots and the shoots in the xylem and phloem, engages ...

where a leaf is attached *In

cladistics Cladistics ( ; from Ancient Greek 'branch') is an approach to Taxonomy (biology), biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesiz ...

, a shared ancestor (also see

Clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...

)

Computing and electronics

Node (networking) In Computer network, networking, a node (, ‘knot’) is either a redistribution point or a communication endpoint within telecommunication networks. A physical network node is an electronic device that is attached to a network, and is capable ...

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

mesh network A mesh network is a local area network topology in which the infrastructure nodes (i.e. bridges, switches, and other infrastructure devices) connect directly, dynamically and non-hierarchically to as many other nodes as possible and cooperate wit ...

Node (circuits) In electrical engineering, a node is any region or joining point on a circuit between two circuit elements. In circuit diagrams, connections are ideal wires with zero resistance. Whether "node" refers to a single point of junction or an entir ...

, 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), tree data structure. Nodes contain data and also may link to other nodes. Links between nodes are often implemented by Pointer (computer programming), point ...

, a basic unit used to build data structures *

Goal node (computer science) In computer science, a goal node is a node in a graph that meets defined criteria for success or termination. Heuristical artificial intelligence algorithms, like A* and B*, attempt to reach such nodes in optimal time by defining the distance ...

, a node in a graph that meets defined criteria for success or termination *

Node (UML) A node in the Unified Modeling Language The Unified Modeling Language (UML) is a general-purpose visual modeling language that is intended to provide a standard way to visualize the design of a system. UML provides a standard notation for ...

, the representation of a computational device in the Unified Modeling Language * Node.js, a JavaScript-based, cross-platform runtime environment *

NodeB {{Unreferenced, date=May 2019, bot=noref (GreenC bot) Node B is the telecommunications node for mobile communication networks, namely those that adhere to the UMTS standard. The Node B provides the connection between mobile phones ( UEs) and th ...

, hardware that is connected to the mobile phone network *

NODE (wireless sensor) NODE+ (wireless sensor platform) is a first-generation handheld sensor measuring 1 inch in diameter and 3.75 inches wide that communicates wirelessly through low-energy Bluetooth 4.0 with Apple iOS devices. In September 2014, 16 interchangeable ...

, a wireless handheld sensor for smart devices *Node, a shorthand used to designate a

semiconductor fabrication process Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuits (ICs) such as microprocessors, microcontrollers, and memories (such as Random-access memory, RAM and flash memory). It is a ...

Linguistics

Node (linguistics) In formal syntax, a node is a point in a Parse tree, tree diagram or Concrete syntax tree, syntactic tree that can be assigned a syntactic category label. Nodes under phrase structure rules Before the emergence of the X-bar theory, thus in the ...

, 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 effe ...

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

Space-station modules

Unity (ISS module) ''Unity'', also known as Node 1, is the first U.S.-built component of the International Space Station (ISS). This cylindrical module, constructed of steel by Boeing for NASA, serves as the critical link between the orbiting laboratory's Russia ...

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 cabi ...

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'' (), also known as the Uzlovoy Module (UM, ) is a Russian-built component of the International Space Station (ISS). This spherical module has six docking ports (forward, aft, port, starboard, zenith, and nadir) to provide additiona ...

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

In music

* Node (band), Italian death metal band * Node (singer), 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, 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, his ear ...

*''New Oxford Dictionary of English'', a single-volume English language dictionary, see

Oxford Dictionary of English The ''Oxford Dictionary of English'' (''ODE'') is a single-volume English dictionary published by Oxford University Press, first published in 1998 as ''The New Oxford Dictionary of English'' (''NODE''). The word "New" was dropped from the titl ...

*Node, a cyborg with a donated human face used as a guide, in " Silence in the Library" (''Doctor Who'') *Node, the pommel-like part of a

chalice A chalice (from Latin 'cup', taken from the Ancient Greek () 'cup') is a drinking cup raised on a stem with a foot or base. Although it is a technical archaeological term, in modern parlance the word is now used almost exclusively for the ...

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

Cellular organizational structure A non-biological entity with a cellular organizational structure (also known as a cellular organization, cellular system, nodal organization, nodal structure, et cetera) is set up in such a way that it mimics how Natural science, natural systems ...

*Node in aroid plant
What is a node?
A node is a small, brown bump on the stem of an aroid plant. It's the point where leaves and aerial roots grow. Nodes contain meristematic tissue, which is responsible for the growth of new roots and shoots.