Shell may refer to:

Architecture and design

Shell (structure) A shell is a type of structural element which is characterized by its geometry, being a three-dimensional solid whose thickness is very small when compared with other dimensions, and in structural terms, by the stress resultants calculated in t ...

, a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses ** Thin-shell structure

Science

Biology

Seashell A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer usually created by an animal or organism that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washe ...

, a hard outer layer of a marine animal, found on beaches *

Eggshell An eggshell is the outer covering of a hard-shelled egg and of some forms of eggs with soft outer coats. Diversity Worm eggs Nematode eggs present a two layered structure: an external vitellin layer made of chitin that confers mechanical ...

* Nutshell *

Exoskeleton An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton ( endoskeleton) in for example, a human. In usage, some of the ...

, an external covering of some animals **

Mollusc shell The mollusc (or molluskOften spelled mollusk shell in the USA; the spelling "mollusc" are preferred by ) shell is typically a calcareous exoskeleton which encloses, supports and protects the soft parts of an animal in the phylum Mollusca, which ...

***

Bivalve shell A bivalve shell is part of the body, the exoskeleton or shell, of a bivalve mollusk. In life, the shell of this class of mollusks is composed of two hinged parts or '' valves''. Bivalves are very common in essentially all aquatic locales, includin ...

***

Gastropod shell The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium s ...

** Shell, of a

brachiopod Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, ...

** Turtle shell

Physics and chemistry

Electron shell In chemistry and atomic physics, an electron shell may be thought of as an orbit followed by electrons around an atom's Atomic nucleus, nucleus. The closest shell to the nucleus is called the "1 shell" (also called the "K shell"), followed by t ...

or a principal energy level of electrons outside an atom's nucleus *

Nuclear shell model In nuclear physics, atomic physics, and nuclear chemistry, the nuclear shell model is a model of the atomic nucleus which uses the Pauli exclusion principle to describe the structure of the nucleus in terms of energy levels. The first shell mo ...

, a principal energy level of nucleons within an atom's nucleus *

On shell and off shell In physics, particularly in quantum field theory, configurations of a physical system that satisfy classical equations of motion are called "on the mass shell" or simply more often on shell; while those that do not are called "off the mass shell" ...

, quantum field theory concepts depending on whether classical equations of motion are obeyed

Mathematics

Spherical shell In geometry, a spherical shell is a generalization of an annulus to three dimensions. It is the region of a ball between two concentric spheres of differing radii. Volume The volume of a spherical shell is the difference between the enclosed vol ...

Organisations

Shell plc Shell plc is a British multinational oil and gas company headquartered in London, England. Shell is a public limited company with a primary listing on the London Stock Exchange (LSE) and secondary listings on Euronext Amsterdam and the New ...

, a British multinational oil and gas company **

Shell USA Shell USA, Inc. (formerly Shell Oil Company, Inc.) is the United States-based wholly owned subsidiary of Shell plc, a UK-based transnational corporation "oil major" which is amongst the largest oil companies in the world. Approximately 18,000 ...

Shell Australia Shell Australia is the Australian subsidiary of Shell. Shell has operated in Australia since 1901, initially delivering bulk fuel into Australia, then establishing storage and distribution terminals, oil refineries, and a network of service st ...

** Shell Canada **

Shell Nigeria Shell Nigeria is the common name for Shell plc's Nigerian operations carried out through four subsidiaries—primarily Shell Petroleum Development Company of Nigeria Limited (SPDC). Royal Dutch Shell's joint ventures account for more than 21% of ...

Shell corporation A shell corporation is a company or corporation that exists only on paper and has no office and no employees, but may have a bank account or may hold passive investments or be the registered owner of assets, such as intellectual property, or ...

, a type of company that serves as a vehicle for business transactions

Computing

Shell (computing) In computing, a shell is a computer program that exposes an operating system's services to a human user or other programs. In general, operating system shells use either a command-line interface (CLI) or graphical user interface (GUI), dependin ...

, a type of user interface ** Command-line interface, sometimes referred to as command shell **

List of command-line interpreters In computing, a command-line interpreter, or command language interpreter, is a blanket term for a certain class of programs designed to read lines of text entered by a user, thus implementing a command-line interface. Operating system shells ...

, programs occasionally referred to as shells **

Web shell A web shell is a shell-like interface that enables a web server to be remotely accessed, often for the purposes of cyberattacks. A web shell is unique in that a web browser is used to interact with it. A web shell could be programmed in any pr ...

, interface that enables a web server to be remotely accessed *

Read–eval–print loop A read–eval–print loop (REPL), also termed an interactive toplevel or language shell, is a simple interactive computer programming environment that takes single user inputs, executes them, and returns the result to the user; a program written ...

, also known as a language shell *

Shell account A shell account is a user account on a remote server, traditionally running under the Unix operating system, which gives access to a shell via a command-line interface protocol such as telnet, SSH, or over a modem using a terminal emulator. S ...

, a user account on a remote server *

Secure Shell The Secure Shell Protocol (SSH) is a cryptographic network protocol for operating network services securely over an unsecured network. Its most notable applications are remote login and command-line execution. SSH applications are based ...

, cryptographic network protocol *

Shellsort Shellsort, also known as Shell sort or Shell's method, is an in-place comparison sort. It can be seen as either a generalization of sorting by exchange (bubble sort) or sorting by insertion ( insertion sort). The method starts by sorting pairs ...

or Shell sort, a sorting algorithm by Donald Shell * Shell, an empty

expert system In artificial intelligence, an expert system is a computer system emulating the decision-making ability of a human expert. Expert systems are designed to solve complex problems by reasoning through bodies of knowledge, represented mainly as if� ...

Entertainment

* ''Shell'' (film) * Shell (theater), a curved surface for reflecting sound *

The Shells The Shells were an American doo wop ensemble formed in Brooklyn, New York, United States, in 1957. The group scored a US pop hit in 1957 with the song "Baby Oh Baby", released on Johnson Records; the song cracked the Top 30. Further singles pa ...

, a musical group * "Shells" (''Angel''), a TV episode * Shell, a receptacle used in the

Shell game The shell game (also known as thimblerig, three shells and a pea, the old army game) is often portrayed as a gambling game, but in reality, when a wager for money is made, it is almost always a confidence trick used to perpetrate fraud. In conf ...

Places

Shell, Ecuador Shell (also Shell Mera) is a city located on the western edge of the Ecuadorian Amazon and in the eastern foothills of the Andes. It is located about southeast of Quito, and roughly west of the provincial capital, Puyo. Its name comes from the R ...

Shell, Wyoming Shell is a census-designated place (CDP) in Big Horn County, Wyoming, United States. The population was 83 at the 2010 Census. The community is named for the abundance of fossil shells located in the area. Nearby exposed formations such as ...

, United States *

Shell Lake (disambiguation) Canada * Shell Lake, Saskatchewan, a community in Saskatchewan ** Shell Lake murders The Shell Lake murders is the name of a mass murder incident committed by Victor Ernest Hoffman (1946 – May 21, 2004) in Shell Lake, Saskatchewan, Canada ...

, several places

Weaponry

Shell (projectile) A shell, in a military context, is a projectile whose payload contains an explosive, incendiary, or other chemical filling. Originally it was called a bombshell, but "shell" has come to be unambiguous in a military context. Modern usage ...

, an explosive device fired from artillery * Shotgun shell, a type of shotgun ammunition

Persons with the surname Shell

* Art Shell (born 1946), American football player and coach *

Brandon Shell Brandon McArthur Shell (born February 6, 1992) is an American football offensive tackle for the Miami Dolphins of the National Football League (NFL). He played college football at South Carolina. He is the great nephew of Pro Football Hall of ...

(born 1992), American football player * Donald Shell (1924–2015), American computer scientist *

Donnie Shell Donnie Shell (born August 26, 1952) is a former American Football strong safety for the Pittsburgh Steelers in the National Football League between 1974 and 1987. Shell was a member of the Steelers famed Steel Curtain defense in the 1970s. Shell ...

(born 1952), American football player *

George W. Shell George Washington Shell (November 13, 1831 – December 15, 1899) was a U.S. Representative from South Carolina. Life Born near Laurens, South Carolina, Shell attended the common schools and Laurens Academy. He engaged in agricultural pursu ...

(1831–1899), U.S. Representative from South Carolina *

Karl Shell Karl Shell (born May 10, 1938) is an American theoretical economist, specializing in macroeconomics and monetary economics. Shell received an A.B. in mathematics from Princeton University in 1960. He earned his Ph.D. in economics in 1965 at ...

(born 1938), American economist

Other uses

Racing shell In watercraft, a racing shell (also referred to as just a ''fine boat'' (UK) or just ''shell'') is an extremely narrow, and often comparatively long, rowing boat specifically designed for racing or exercise. It is outfitted with long oars, outrig ...

, a watercraft *

Shell (machinery) A plain bearing, or more commonly sliding contact bearing and slide bearing (in railroading sometimes called a solid bearing, journal bearing, or friction bearing), is the simplest type of bearing, comprising just a bearing surface and no rolli ...

, each half of a two-piece plain bearing * Coverage shell, the number of defenders guarding the deep portion of the field in American football *

Conchiglie Conchiglie (), commonly known as "shells" or "seashells", is a type of pasta. It is usually sold in the plain durum wheat variety, and also in colored varieties which use natural pigments, such as tomato extract, squid ink or spinach extract. Th ...

, a type of pasta