A group is a

number A number is a mathematical object used to count, measure, and label. The original examples are the natural numbers 1, 2, 3, 4, and so forth. Numbers can be represented in language with number words. More universally, individual numbers c ...

of persons or things that are located, gathered, or classed together.

Groups of people

* Cultural group, a group whose members share the same cultural identity *

Ethnic group An ethnic group or an ethnicity is a grouping of people who identify with each other on the basis of shared attributes that distinguish them from other groups. Those attributes can include common sets of traditions, ancestry, language, history, ...

, a group whose members share the same ethnic identity * Religious group (disambiguation), a group whose members share the same religious identity *

Social group In the social sciences, a social group can be defined as two or more people who interact with one another, share similar characteristics, and collectively have a sense of unity. Regardless, social groups come in a myriad of sizes and varieties ...

, a group whose members share the same social identity *

Tribal group The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide usage of the term in English is in the discipline of anthropology. This definition is contested, in part due to conflic ...

, a group whose members share the same tribal identity *

Organization An organization or organisation (Commonwealth English; see spelling differences), is an entity—such as a company, an institution, or an association—comprising one or more people and having a particular purpose. The word is derived from ...

, an entity that has a collective goal and is linked to an external environment * Peer group, an entity of three or more people with similar age, ability, experience, and interest

Social science

In-group and out-group In sociology and social psychology, an in-group is a social group to which a person psychologically identifies as being a member. By contrast, an out-group is a social group with which an individual does not identify. People may for example ide ...

* Primary, secondary, and reference groups *

* Collectives

Science and technology

Mathematics

Group (mathematics) In mathematics, a group is a Set (mathematics), set and an Binary operation, operation that combines any two Element (mathematics), elements of the set to produce a third element of the set, in such a way that the operation is Associative propert ...

, a set together with a binary operation satisfying certain algebraic conditions

Chemistry

Functional group In organic chemistry, a functional group is a substituent or moiety in a molecule that causes the molecule's characteristic chemical reactions. The same functional group will undergo the same or similar chemical reactions regardless of the rest ...

, a group of atoms which provide some property to a molecule * Group (periodic table), a column in the periodic table of chemical elements

Computing and the Internet

Group (computing) In computing, the term group generally refers to a grouping of users. In principle, users may belong to none, one, or many groups (although in practice some systems place limits on this.) The primary purpose of user groups is to simplify access c ...

, a collection of users or other objects *

Group (database) Group is a name service database used to store group information on Unix-like operating systems. The sources for the group database (and hence the sources for groups on a system) are configured, like other name service databases, in nsswitch.conf ...

Group (online social networking) A group (often termed as a community, e-group or club) is a feature in many social networking services which allows users to create, post, comment to and read from their own interest- and niche-specific forums, often within the realm of virtual co ...

Usenet newsgroup A Usenet newsgroup is a repository usually within the Usenet system, for messages posted from users in different locations using the Internet. They are discussion groups and are not devoted to publishing news. Newsgroups are technically distinct ...

* Google Groups *

Yahoo! Groups Yahoo! Groups was a free-to-use system of electronic mailing lists offered by Yahoo!. Prior to February 2020, Yahoo! Groups was one of the world's largest collections of online discussion boards. It allowed members to subscribe to various grou ...

Facebook groups Facebook is a social-network service website launched on February 4, 2004 by Mark Zuckerberg. The following is a list of software and technology features that can be found on the Facebook website and mobile app and are available to users of ...

Other uses in science and technology

Group (stratigraphy) In geology, a group is a lithostratigraphic unit consisting of a series of related formations that have been classified together to form a group. Formations are the fundamental unit of stratigraphy. Groups may sometimes be combined into superg ...

, in geology, consisting of formations or rock strata *

Cultivar group A Group (previously cultivar-groupInternational Code of Nomenclature for Cultivated Plants, 4th edition (1969), 5th edition (1980) and 6th edition (1995)) is a formal category in the ''International Code of Nomenclature for Cultivated Plants'' ('' ...

, in biology, a classification category in the ''International Code of Nomenclature for Cultivated Plants'' *

Galaxy groups and clusters Galaxy groups and clusters are the largest known gravitationally bound objects to have arisen thus far in the process of cosmic structure formation. They form the densest part of the large-scale structure of the Universe. In models for the gravit ...

, in cosmology *

Group (firearms) In shooting sports, a shot grouping, or simply group, is the collective pattern of projectile impacts on a target from multiple consecutive shots taken in one shooting session. The ''tightness'' of the grouping (the proximity of all the shots to ...

, the grouping of shots from a firearm * Language group, a unit of classification within a

Language family A language family is a group of languages related through descent from a common ''ancestral language'' or ''parental language'', called the proto-language of that family. The term "family" reflects the tree model of language origination in hist ...

Other uses

Breed Groups (dog) Dog types are broad categories of domestic dogs based on form, function, or style of work, lineage, or appearance. Some may be locally adapted dog types (or ''landraces'') that may have the visual characteristics of a modern purebred dog. In c ...

, the group or category to which breeds of dogs are assigned by kennel clubs *

Group (auto racing) A FIA Group is a category of car allowed to compete in auto racing. The FIA Appendix J to the international motor sports code defines the various Groups. While a given racing car may fit into a FIA Group, local rules still may either prohibit the ...

, a category of car allowed to compete in auto racing *

Army group An army group is a military organization consisting of several field armies, which is self-sufficient for indefinite periods. It is usually responsible for a particular geographic area. An army group is the largest field organization handled by ...

Militia groups A militia () is generally an army or some other fighting organization of non-professional soldiers, citizens of a country, or subjects of a state, who may perform military service during a time of need, as opposed to a professional force of r ...

Rebel groups Rebellion, uprising, or insurrection is a refusal of obedience or order. It refers to the open resistance against the orders of an established authority. A rebellion originates from a sentiment of indignation and disapproval of a situation and ...

Terrorist groups A number of national governments and two international organizations have created lists of organizations that they designate as terrorist. The following list of designated terrorist groups lists groups designated as terrorist by current and fo ...

* Group (military unit), an air force formation *

Corporate group A corporate group or group of companies is a collection of parent and subsidiary corporations that function as a single economic entity through a common source of control. These types of groups are often managed by an account manager. The concep ...

, a group of affiliated companies *

Group psychotherapy Group psychotherapy or group therapy is a form of psychotherapy in which one or more therapists treat a small group of clients together as a group. The term can legitimately refer to any form of psychotherapy when delivered in a group format, ...

, sometimes colloquially known as "group" *

Musical ensemble A musical ensemble, also known as a music group or musical group, is a group of people who perform instrumental and/or vocal music, with the ensemble typically known by a distinct name. Some music ensembles consist solely of instrumentalists, ...