Art was a Roman concept and that word equated with a skill regulated by rules of procedure. Alternately,  a profession, a pursuit, or a business. In medieval times this word was understood to identify a skill, or ability to perform certain acts following observation, study and accumulated experience. Since art was seen as a discipline,  it became engrafted onto scholastic and academic pursuits to describe various branches of  book learning., hence the Liberal Arts. Any systematic application of knowledge aimed at producing  a product, ie. a craft, was also regarded as an art form, thus we hear of the Industial or Mechanical Arts.