Earth art, also known as land art, earthworks, or environmental art, involves creating artworks directly in nature using natural materials like stones, leaves, mud, and twigs. The document discusses several earth artists like Andy Goldsworthy, Robert Smithson, and Richard Long. It provides examples of their artworks, which are typically large-scale sculptures or installations created outdoors using materials found in the natural environment. The emergence of earth art in the 1960s-70s was influenced by a reaction against commercialism and a desire to create art outside the gallery setting and integrate it with the natural world.