In the history of art, prehistoric art is all art

Art

Art is the product or process of deliberately arranging items in a way that influences and affects one or more of the senses, emotions, and intellect....

 produced in preliterate, prehistorical

Prehistory

Prehistory is the span of time before recorded history. Prehistory can refer to the period of human existence before the availability of those written records with which recorded history begins. More broadly, it refers to all the time preceding human existence and the invention of writing...

 cultures beginning somewhere in very late geological history, and generally continuing until that culture either develops writing or other methods of record-keeping, or it makes significant contact with another culture that has.

The very earliest human artifacts showing evidence of workmanship with an artistic purpose are a subject of some debate; it is clear that such workmanship existed by 40,000 years ago in the Upper Palaeolithic era.