Separation of concerns in the context of Component-based software engineering

Modular programming is a programming paradigm that emphasizes organizing the functions of a codebase into independent modules – each providing an aspect of a computer program in its entirety without providing other aspects.

A module interface expresses the elements that are provided and required by the module. The elements defined in the interface are detectable by other modules. The implementation contains the working code that corresponds to the elements declared in the interface.

In computing, an abstraction layer or abstraction level is a way of hiding the working details of a subsystem. Examples of software models that use layers of abstraction include the OSI model for network protocols, OpenGL, and other graphics libraries, which allow the separation of concerns to facilitate interoperability and platform independence.

In computer science, an abstraction layer is a generalization of a conceptual model or algorithm, away from any specific implementation. These generalizations arise from broad similarities that are best encapsulated by models that express similarities present in various specific implementations. The simplification provided by a good abstraction layer allows for easy reuse by distilling a useful concept or design pattern so that situations, where it may be accurately applied, can be quickly recognized. Just composing lower-level elements into a construct doesn't count as an abstraction layer unless it shields users from its underlying complexity.

A web style sheet is a form of separation of content and presentation for web design in which the markup (i.e., HTML or XHTML) of a webpage contains the page's semantic content and structure, but does not define its visual layout (style). Instead, the style is defined in an external style sheet file using a style sheet language such as CSS or XSLT. This design approach is identified as a "separation" because it largely supersedes the antecedent methodology in which a page's markup defined both style and structure.

The philosophy underlying this methodology is a specific case of separation of concerns.

A software component is a modular unit of software that encapsulates specific functionality. The desired characteristics of a component are reusability and maintainability.