Installation art is a form of contemporary art. Installation art refers to any work that is site-specific and uses a variety of materials. It is one of today's most popular forms of contemporary art.
Installation art first came around in the late 1910s, with Marcel Duchamp's Fountain, a controversial piece involving a urinal. The first 'real' installation pieces were in the 70s and 80s by artists such as Wolf Vostell and Allan Kaprow. Installation art goes hand in hand with other art forms like video art and performance art, both of which were pioneered earlier. Most of the time, installation art focusses on themes and meaning behind the work.