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. a notion that Joseph Kosuth elevated to a definition of art itself in his seminal, early manifesto of conceptual art, "Art after Philosophy" (1969).
According to Greenberg Modern art followed a process of progressive reduction and refinement toward the goal of defining the essential, formal nature of each medium.
Some works of conceptual art, sometimes called installations, may be constructed by anyone simply by following a set of written instructions.
Although the utilisation of text in art was in no way novel, only in the 1960s did the artists Lawrence Weiner, Edward Ruscha, Joseph Kosuth, Robert Barry, and the English Art & Language group begin to produce art by exclusively linguistic means.