Art historians categorize art in periods and movements throughout time. Beginning with Neolithic and Paleolithic art, the periods and movements stretch from 30,000 BCE to modern day. Art movements are different than art periods. Movements are defined by the artists in them and often have a common goal (like Romanticism). An art period is simply art that is created within a certain time span that has similar qualities. As shown by the graph to the left, the periods and movements overlap throughout time depending on location, social movements, and other historical events.