The related terms "artwork" and "art object", used especially in American English, came into use in the 20th century, especially to describe modern and post-modern art, in order to avoid an older syntagma "piece of art" as a concept which was strongly tied with traditional aesthetics.

To establish whether a work is a work of art, the concepts of attribution, artistic merit and literary merit may be invoked.

The French form of "art object", objet d'art, has been used for much longer in English and usually means a work of decorative or applied art.

Among practitioners of contemporary art, various new media objects such as the DVD, the web page, and other interactive media have been treated as art objects; such treatment frequently involves a formalist (or "medium-specific") analysis. The formal analysis of computerized media has yielded such art movements as internet art and algorithmic art. The purpose of "new media objects" is not to replace traditional media, but to challenge old media.

Art is the process or product of deliberately and creatively arranging elements in a way that appeals to the senses or emotions. In its narrow sense, the word art most often refers specifically to the visual arts, including media such as painting, sculpture, and printmaking. However, "the arts" may also encompass a diverse range of human activities, creations, and modes of expression, including music and literature. Aesthetics is the branch of philosophy which studies art.

Traditionally, the term art was used to refer to any skill or mastery. This conception changed during the Romantic period, when art came to be seen as "a special faculty of the human mind to be classified with religion and science". Generally, art is a human activity, made with the intention of stimulating thoughts and emotions. Beyond this description, there is no general agreed-upon definition of art.

The definition and evaluation of art has become especially problematic since the 20th century. Richard Wollheim distinguishes three approaches: the Realist, whereby aesthetic quality is an absolute value independent of any human view; the Objectivist, whereby it is also an absolute value, but is dependent on general human experience; and the Relativist position, whereby it is not an absolute value, but depends on, and varies with, the human experience of different humans. An object may be characterized by the intentions, or lack thereof, of its creator, regardless of its apparent purpose. A cup, which ostensibly can be used as a container, may be considered art if intended solely as an ornament, while a painting may be deemed craft if mass-produced.

Visual art is defined as the arrangement of colors, forms, or other elements "in a manner that affects the sense of beauty, specifically the production of the beautiful in a graphic or plastic medium". The nature of art has been described by Wollheim as "one of the most elusive of the traditional problems of human culture". It has been defined as a vehicle for the expression or communication of emotions and ideas, a means for exploring and appreciating formal elements for their own sake, and as mimesis or representation. Leo Tolstoy identified art as a use of indirect means to communicate from one person to another. Benedetto Croce and R.G. Collingwood advanced the idealist view that art expresses emotions, and that the work of art therefore essentially exists in the mind of the creator. The theory of art as form has its roots in the philosophy of Immanuel Kant, and was developed in the early twentieth century by Roger Fry and Clive Bell. Art as mimesis or representation has deep roots in the philosophy of Aristotle.