Component

Component may refer to:

Software

Component (UML)

A component in the Unified Modeling Language "represents a modular part of a system, that encapsulates its content and whose manifestation is replaceable within its environment. A component defines its behavior in terms of provided and required interfaces".

A component may be replaced by another if and only if their provided and required interfaces are identical. This idea is the underpinning for the plug-and-play capability of component-based systems and promotes software reuse.

As can be seen from the above definition, UML places no restriction on the granularity of a component. Thus, a component may be as small as a figures-to-words converter, or as large as an entire document management system.

Larger pieces of a system's functionality may be assembled by reusing components as parts in an encompassing component or assembly of components, and wiring together their required and provided interfaces." Such assemblies are illustrated by means of component diagrams.

Related terms

Component-based software engineering

Component-based software engineering (CBSE) (also known as component-based development (CBD)) is a branch of software engineering that emphasizes the separation of concerns in respect of the wide-ranging functionality available throughout a given software system. It is a reuse-based approach to defining, implementing and composing loosely coupled independent components into systems. This practice aims to bring about an equally wide-ranging degree of benefits in both the short-term and the long-term for the software itself and for organizations that sponsor such software.

Software engineering practitioners regard components as part of the starting platform for service-orientation. Components play this role, for example, in web services, and more recently, in service-oriented architectures (SOA), whereby a component is converted by the web service into a service and subsequently inherits further characteristics beyond that of an ordinary component.

Components can produce or consume events and can be used for event-driven architectures (EDA).