Separation of content and presentation

Separation of content and presentation (or separation of content and style) is the separation of concerns design principle as applied to the authoring and presentation of content. Under this principle, visual and design aspects (presentation and style) are separated from the core material and structure (content) of a document. A typical analogy used to explain this principle is the distinction between the human skeleton (as the structural component) and human flesh (as the visual component) which makes up the body's appearance. Common applications of this principle are seen in Web design (HTML vs. CSS) and document typesetting (Lambert's document body vs. its preamble).