We can easily recognize representational or realistic works of art. In this style an artist will try to capture a subject as seen by the human eye or at least closely resembling it. Some representational art is more realistic than others. Above there are three different examples of Realism. The first shows a black and white two-dimensional image that is rendered to be almost identical to the subject. The second image is a landscape that although containing realistic information and proportion the colors and the stabilization of the actual elements such as the tree are rendered in a somewhat illustrative and cartoon like manner. The third is an image of a three-dimensional sculpture that captures the true form of hand and cloth. It is almost hyper-realistic where it becomes too perfect to be real. Although all three of these show different characteristics they are all examples of an artist demonstrating the reality of the viewer.
Abstract art captures subjects from reality but presents them in ways that are different from the way they are viewed in our reality. This may be demonstrated by emphasizing lines, shapes, or colors that transform the subject. The Elements of Art are often used to distort, exaggerate or simplify so that the subject matter is not always immediately recognizable.
All of the images above are examples of abstraction. In the first image we can see that artist is portraying people possibly in a band playing music together. Although we cannot see any detail within the people or the instruments we can still recognize what they represent. The following two images by Salvador Dali and Pablo Picasso both show instances of reality warped by using color and shape and greatly exaggerating and simplifying their images. Dali uses more exaggeration and extreme contrast of value and Picasso simplifies his image into shapes and colors.
Non-Objective art takes nothing from reality. It is created purely for aesthetic reasons. The intent of Non-objective art is to use the elements and principles of art in a way that results in a visually stimulating work. The artist aims to convey a sense of simplicity and purity. The art does not represent a person, place or thing in the natural world.
Above and below you can see works don by Jasper Johns, Jackson Pollock, Piet Mondrian, Kandinsky, Mark Rothko, Vasarely, and Clyfford Still. These artists choose various Elements of art to focus on as the subject alone. Mark Rothko is known for his color study and Pollock for his "splatter-like" style. Mondrian and Johns focus heavily on color and shape. One being extremely geometric while the other tends to be more organic in application.