Above is a piece by michelangelo, called the holy family. explain the term modeling in art and why michelangelo was considered a master of modeling.

To model means to give shape or form to something. According to a dictionary definition, modeling is "the technique of rendering the illusion of volume on a two-dimensional surface by shading. "Assuming you have this in mind, you can see some exquisite shading in the painting done by Michelangelo, especially on the blue skirt, or cloth this person is wearing. In order to create something more vivid and life-like, Michelangelo applied this technique to most of his paintings, and it is obvious in this one as well.  

lithograph is created by etching the flat surface of a print.