Loosely any outline, sketch or plan, as of the form and structure of a work of art, an edifice or a machine to be executed or constructed.

More specifically, as an art form, it is used to refer to the organisation or structure of formal elements: composition. There is a general assumption that design serves some purpose outside of the work itself. In other words, design marries art and strategy. It is the art of combining strategy and aesthetic to perform a function. Building design is here treated separately as architecture.