Mail art is a worldwide cultural movement that began in the early 1960s and involves sending visual art (but also music, sound art, poetry, etc.) through the international postal system. Mail Art is also known as Postal Art or Correspondence Art. The term networking is often used to describe Mail Art activities, based on the principles of barter and equal one-to-one collaboration.

After a peak in popularity in the late 1980s and early 1990s, the Mail Art phenomenon has gradually migrated to the Internet, whose “social networks” were largely anticipated and predicted by the interactive processes of postal collaborations. Nevertheless, Mail Art is still practiced in the new Millennium by a loose global community involving thousands of mailartists from the most varied backgrounds.

"Out of the reasonable assumption that the commercial gallery system is limited and perhaps corrupt, many artists emerging in the 1970s and 1980s around the world decided it would be more feasible to exhibit their work not through galleries and ancillary museums but through the postal system, especially if they lived in areas where galleries and other artists were scarce. For the production of imagery, they drew often upon xerography (photocopying) and the earlier technology of rubber stamps. They would also announce exhibitions in venues previously devoid of art, such as city halls in remote parts of the world, ideally accepting everything submitted and issuing a catalog with names, usually accompanied by addresses and selected reproductions. While such work had little impact upon commercial galleries (and the "art magazines" dependent upon galleries' ads), one result was a thriving alternative culture, calling itself "The Eternal Network", as intensely interested in itself as serious artists have always been."

Art is a term that describes a diverse range of human activities and the products of those activities, but is most often understood to refer to painting, film, photography, sculpture, and other visual media. Music, theatre, dance, literature, and interactive media are included in a broader definition of art or the arts. Until the 17th century, art referred to any skill or mastery and was not differentiated from crafts or sciences, but in modern usage the fine arts are distinguished from acquired skills in general.

Many definitions of art have been proposed by philosophers and others who have characterized art in terms of mimesis, expression, communication of emotion, or other values. During the Romantic period, art came to be seen as "a special faculty of the human mind to be classified with religion and science".

The nature of art, and related concepts such as creativity and interpretation, are explored in a branch of philosophy known as aesthetics.

The Encyclopædia Britannica Online defines art as "the use of skill and imagination in the creation of aesthetic objects, environments, or experiences that can be shared with others". By this definition of the word, artistic works have existed for almost as long as humankind: from early pre-historic art to contemporary art; however, some theories restrict the concept to modern Western societies. The first and broadest sense of art is the one that has remained closest to the older Latin meaning, which roughly translates to "skill" or "craft." A few examples where this meaning proves very broad include artifact, artificial, artifice, medical arts, and military arts. However, there are many other colloquial uses of the word, all with some relation to its etymology.