The term conceptual art came into use about 1965, to describe art in which the artist's propositional concept is of primary importance but the manner and matter of execution are de-emphasized. The term was defined (1967) by Sol Lewitt, a pioneer and theorist in conceptual art. Subsumed under the term are diverse forms of written or visual documentation, including textual data, handwritten descriptions, typed instructions, diagrams, drawings, maps, photographic records, and oral communication.

Duration Series #5 Douglas Huebler (1969)

Stressing the use of language and thought processes as such, and utilizing facts in the literal sense, conceptual art has been widely regarded as the culmination of the penetration of art by written information, a phenomenon that proliferated during the 1950s and '60s. In its minimalization of the permanent and visual object, conceptual art is also a statement of widespread disenchantment with the commercial gallery and museum system among artists of the 1960s and early 1970s. 

Serial Project 7 Sol Lewitt (1966)		Incomplete Open Space Sol Lewitt (1974)

Some of the key exponents of conceptual art include Sol LeWitt, Joseph Kosuth, Robert Barry, Donald Burgy, Daniel Buren, Ian Dibbets, Douglas Huebler, Bruce Nauman, and Richard Serra.

"In conceptual art the idea or concept is the most important aspect of the work. When an artist uses a conceptual form of art, it means that all of the planning and decisions are made beforehand and the execution is a perfunctory affair. The idea becomes a machine that makes the art." – Sol LeWitt, "Paragraphs on Conceptual Art", Artforum, June 1967.

This quotation highlights a key difference between a conceptual art installation and a traditional work of art:

• The conceptual artist's work may require little or no physical craftsmanship in its execution,
• Traditional art is distinguished from conceptual art by requiring physical skill and the making of aesthetic choices.

Please note that it is not always entirely clear what "concept" ultimately refers to, and it runs the risk of being confused with "intention."Therefore, in describing or defining a work of art as conceptual it is important not to confuse what is referred to as "conceptual" with an artist's "intention."