Category, plural categories, may refer to:

General uses

Classification Classification is the activity of assigning objects to some pre-existing classes or categories. This is distinct from the task of establishing the classes themselves (for example through cluster analysis). Examples include diagnostic tests, identif ...

, the general act of allocating things to classes/categories

Philosophy

Category of being In ontology, the theory of categories concerns itself with the ''categories of being'': the highest ''genera'' or ''kinds of entities''. To investigate the categories of being, or simply categories, is to determine the most fundamental and the br ...

* ''Categories'' (Aristotle) *

Category (Kant) In Immanuel Kant's philosophy, a category ( in the original or ''Kategorie'' in modern German) is a pure concept of the understanding (''Verstand''). A Kantian category is a characteristic of the appearance of any object in general, before it ha ...

Categories (Peirce) On May 14, 1867, the 27–year-old Charles Sanders Peirce, who eventually founded pragmatism, presented a paper entitled " On a New List of Categories" to the American Academy of Arts and Sciences. Among other things, this paper outlined a theory ...

Category (Vaisheshika) Category, plural categories, may refer to: General uses *Classification, the general act of allocating things to classes/categories Philosophy * Category of being * ''Categories'' (Aristotle) * Category (Kant) * Categories (Peirce) * Category ( ...

* Stoic categories *

Category mistake A category mistake (or category error, categorical mistake, or mistake of category) is a semantic or ontological error in which things belonging to a particular category are presented as if they belong to a different category, or, alternatively, ...

Science

Cognitive categorization Categorization is a type of cognition involving conceptual differentiation between characteristics of conscious experience, such as objects, events, or ideas. It involves the abstraction and differentiation of aspects of experience by sorting ...

, categories in cognitive science *

Statistical classification When classification is performed by a computer, statistical methods are normally used to develop the algorithm. Often, the individual observations are analyzed into a set of quantifiable properties, known variously as explanatory variables or ''f ...

, statistical methods used to effect classification/categorization

Mathematics

Category (mathematics) In mathematics, a category (sometimes called an abstract category to distinguish it from a concrete category) is a collection of "objects" that are linked by "arrows". A category has two basic properties: the ability to compose the arrows asso ...

, a structure consisting of objects and arrows * Category (topology), in the context of Baire spaces *

Lusternik–Schnirelmann category In mathematics, the Lyusternik–Schnirelmann category (or, Lusternik–Schnirelmann category, LS-category) of a topological space X is the homotopy invariant defined to be the smallest integer number k such that there is an open covering \_ of X ...

, sometimes called ''LS-category'' or simply ''category'' *

Categorical data In statistics, a categorical variable (also called qualitative variable) is a variable (research), variable that can take on one of a limited, and usually fixed, number of possible values, assigning each individual or other unit of observation to a ...

, in statistics

Linguistics

Lexical category In grammar, a part of speech or part-of-speech (abbreviated as POS or PoS, also known as word class or grammatical category) is a category of words (or, more generally, of lexical items) that have similar grammatical properties. Words that are ass ...

, a part of speech such as ''noun'', ''preposition'', etc. *

Syntactic category A syntactic category is a syntactic unit that theories of syntax assume. Word classes, largely corresponding to traditional parts of speech (e.g. noun, verb, preposition, etc.), are syntactic categories. In phrase structure grammars, the ''phrasa ...

, a similar concept which can also include phrasal categories *

Grammatical category In linguistics, a grammatical category or grammatical feature is a property of items within the grammar of a language. Within each category there are two or more possible values (sometimes called grammemes), which are normally mutually exclusive ...

, a grammatical feature such as ''tense'', ''gender'', etc.

Other

Category (chess tournament) A chess tournament is a series of chess games played competitively to determine a winning individual or team. Since the first international chess tournament in London 1851 chess tournament, London, 1851, chess tournaments have become the standard ...

* Objective-C categories, a computer programming concept *

Pregnancy category The pregnancy category of a medication is an assessment of the risk of fetal injury due to the pharmaceutical, if it is used as directed by the mother during pregnancy. It does ''not'' include any risks conferred by pharmaceutical agents or their ...

Prisoner security categories in the United Kingdom In the United Kingdom, prisoners are divided into four categories of security. Each adult is assigned to a category according to their crime, sentence, the risk of escape, and violent tendencies. The categories are designated with the letters A ...

Weight class (boxing) In boxing, a weight class is a measurement Human weight, weight range for boxers. The lower limit of a weight class is equal to the upper weight limit of the class below it. The top class, with no upper limit, is called heavyweight in professi ...

List of software categories Software categories are groups of software. They allow software to be understood in terms of those categories, instead of the particularities of each package. Different classification schemes consider different aspects of software. Categorization ...

Categories (word game) Categories is a word game where players attempt to list words that fit into particular categories, all starting with the same letter. Players start by deciding on a list of categories between them, such as "town" or "actor", and each writing that ...

, a classic party game * Saffir–Simpson hurricane wind scale, a common categorization of hurricane intensities *

Categories of New Testament manuscripts New Testament manuscripts in Greek can be categorized into five theoretical groups, according to a schema introduced in 1981 by Kurt and Barbara Aland in ''The Text of the New Testament''. The categories are based on how each manuscript relat ...

* Network cable categories: 1, 2, 3, 4, 5/5e, 6/6a, 7/7a (F) * A classification in a system of